diff --git a/apps/fwd/src/main/java/org/onlab/onos/fwd/ReactiveForwarding.java b/apps/fwd/src/main/java/org/onlab/onos/fwd/ReactiveForwarding.java
index aaf5350..564a2da 100644
--- a/apps/fwd/src/main/java/org/onlab/onos/fwd/ReactiveForwarding.java
+++ b/apps/fwd/src/main/java/org/onlab/onos/fwd/ReactiveForwarding.java
@@ -184,13 +184,13 @@
 
             // Install the flow rule to handle this type of message from now on.
             Ethernet inPkt = context.inPacket().parsed();
-            TrafficSelector.Builder builder = new DefaultTrafficSelector.Builder();
+            TrafficSelector.Builder builder = DefaultTrafficSelector.builder();
             builder.matchEthType(inPkt.getEtherType())
                 .matchEthSrc(inPkt.getSourceMAC())
                 .matchEthDst(inPkt.getDestinationMAC())
                 .matchInport(context.inPacket().receivedFrom().port());
 
-            TrafficTreatment.Builder treat = new DefaultTrafficTreatment.Builder();
+            TrafficTreatment.Builder treat = DefaultTrafficTreatment.builder();
             treat.setOutput(portNumber);
 
             FlowRule f = new DefaultFlowRule(context.inPacket().receivedFrom().deviceId(),
diff --git a/cli/src/main/java/org/onlab/onos/cli/net/IntentInstallCommand.java b/cli/src/main/java/org/onlab/onos/cli/net/IntentInstallCommand.java
new file mode 100644
index 0000000..90b7311
--- /dev/null
+++ b/cli/src/main/java/org/onlab/onos/cli/net/IntentInstallCommand.java
@@ -0,0 +1,57 @@
+package org.onlab.onos.cli.net;
+
+import org.apache.karaf.shell.commands.Argument;
+import org.apache.karaf.shell.commands.Command;
+import org.onlab.onos.cli.AbstractShellCommand;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.flow.DefaultTrafficSelector;
+import org.onlab.onos.net.flow.DefaultTrafficTreatment;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.intent.HostToHostIntent;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.IntentService;
+
+/**
+ * Lists all shortest-paths paths between the specified source and
+ * destination devices.
+ */
+@Command(scope = "onos", name = "add-intent",
+         description = "Installs HostToHostIntent between the specified source and destination devices")
+public class IntentInstallCommand extends AbstractShellCommand {
+
+    @Argument(index = 0, name = "src", description = "Source device ID",
+              required = true, multiValued = false)
+    String src = null;
+
+    @Argument(index = 1, name = "dst", description = "Destination device ID",
+              required = true, multiValued = false)
+    String dst = null;
+
+    private static long id = 1;
+
+    @Override
+    protected void execute() {
+        IntentService service = get(IntentService.class);
+        HostService hosts = get(HostService.class);
+
+        HostId srcId = HostId.hostId(src);
+        HostId dstId = HostId.hostId(dst);
+
+        TrafficSelector.Builder builder = DefaultTrafficSelector.builder();
+        builder.matchEthSrc(hosts.getHost(srcId).mac())
+                .matchEthDst(hosts.getHost(dstId).mac());
+
+        TrafficTreatment.Builder treat = DefaultTrafficTreatment.builder();
+
+        HostToHostIntent intent =
+                new HostToHostIntent(new IntentId(id++), srcId, dstId,
+                                     builder.build(), treat.build());
+
+        log.info("Adding intent {}", intent);
+
+        service.submit(intent);
+    }
+
+}
diff --git a/cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml b/cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml
index 16b5672..a096735 100644
--- a/cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml
+++ b/cli/src/main/resources/OSGI-INF/blueprint/shell-config.xml
@@ -57,6 +57,13 @@
             </completers>
         </command>
         <command>
+            <action class="org.onlab.onos.cli.net.IntentInstallCommand"/>
+            <completers>
+                <ref component-id="hostIdCompleter"/>
+            </completers>
+        </command>
+
+        <command>
             <action class="org.onlab.onos.cli.net.ClustersListCommand"/>
         </command>
         <command>
diff --git a/core/api/src/main/java/org/onlab/onos/net/DefaultEdgeLink.java b/core/api/src/main/java/org/onlab/onos/net/DefaultEdgeLink.java
index 6074c67..74991c8 100644
--- a/core/api/src/main/java/org/onlab/onos/net/DefaultEdgeLink.java
+++ b/core/api/src/main/java/org/onlab/onos/net/DefaultEdgeLink.java
@@ -18,9 +18,9 @@
      * @param providerId   provider identity
      * @param hostPoint    host-side connection point
      * @param hostLocation location where host attaches to the network
-     * @param isIngress    true to indicated host-to-network direction; false
+     * @param isIngress    true to indicate host-to-network direction; false
      *                     for network-to-host direction
-     * @param annotations optional key/value annotations
+     * @param annotations  optional key/value annotations
      */
     public DefaultEdgeLink(ProviderId providerId, ConnectPoint hostPoint,
                            HostLocation hostLocation, boolean isIngress,
@@ -42,4 +42,20 @@
     public HostLocation hostLocation() {
         return hostLocation;
     }
+
+    /**
+     * Creates a phantom edge link, to an unspecified end-station. This link
+     * does not represent any actually discovered link stored in the system.
+     *
+     * @param edgePort  network edge port
+     * @param isIngress true to indicate host-to-network direction; false
+     *                  for network-to-host direction
+     * @return new phantom edge link
+     */
+    public static DefaultEdgeLink createEdgeLink(HostLocation edgePort,
+                                                 boolean isIngress) {
+        return new DefaultEdgeLink(ProviderId.NONE,
+                                   new ConnectPoint(HostId.NONE, PortNumber.P0),
+                                   edgePort, isIngress);
+    }
 }
diff --git a/core/api/src/main/java/org/onlab/onos/net/HostId.java b/core/api/src/main/java/org/onlab/onos/net/HostId.java
index 1768f24..f2c0303 100644
--- a/core/api/src/main/java/org/onlab/onos/net/HostId.java
+++ b/core/api/src/main/java/org/onlab/onos/net/HostId.java
@@ -10,6 +10,14 @@
  */
 public final class HostId extends ElementId {
 
+    private static final String NIC = "nic";
+
+    /**
+     * Represents either no host, or an unspecified host; used for creating
+     * open ingress/egress edge links.
+     */
+    public static final HostId NONE = hostId(NIC + ":none-0");
+
     // Public construction is prohibited
     private HostId(URI uri) {
         super(uri);
@@ -43,8 +51,7 @@
      * @return host identifier
      */
     public static HostId hostId(MacAddress mac, VlanId vlanId) {
-        // FIXME: use more efficient means of encoding
-        return hostId("nic" + ":" + mac + "-" + vlanId);
+        return hostId(NIC + ":" + mac + "-" + vlanId);
     }
 
     /**
diff --git a/core/api/src/main/java/org/onlab/onos/net/PortNumber.java b/core/api/src/main/java/org/onlab/onos/net/PortNumber.java
index cfb11d5..60c3305 100644
--- a/core/api/src/main/java/org/onlab/onos/net/PortNumber.java
+++ b/core/api/src/main/java/org/onlab/onos/net/PortNumber.java
@@ -9,6 +9,8 @@
  */
 public final class PortNumber {
 
+    public static final PortNumber P0 = portNumber(0);
+
     // TODO: revisit the max and the logical port value assignments
 
     private static final long MAX_NUMBER = (2L * Integer.MAX_VALUE) + 1;
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficSelector.java b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficSelector.java
index d792c7e..31c53a8 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficSelector.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficSelector.java
@@ -1,36 +1,43 @@
 package org.onlab.onos.net.flow;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Objects;
-import java.util.Set;
-
+import com.google.common.collect.ImmutableSet;
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.flow.criteria.Criteria;
 import org.onlab.onos.net.flow.criteria.Criterion;
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
-import org.slf4j.Logger;
 
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+/**
+ * Default traffic selector implementation.
+ */
 public final class DefaultTrafficSelector implements TrafficSelector {
 
-    private final Set<Criterion> selector;
+    private final Set<Criterion> criteria;
 
-    private DefaultTrafficSelector(Set<Criterion> selector) {
-        this.selector = Collections.unmodifiableSet(selector);
+    /**
+     * Creates a new traffic selector with the specified criteria.
+     *
+     * @param criteria criteria
+     */
+    private DefaultTrafficSelector(Set<Criterion> criteria) {
+        this.criteria = Collections.unmodifiableSet(criteria);
     }
 
     @Override
     public Set<Criterion> criteria() {
-        return selector;
+        return criteria;
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(selector);
+        return Objects.hash(criteria);
     }
 
     @Override
@@ -40,23 +47,50 @@
         }
         if (obj instanceof DefaultTrafficSelector) {
             DefaultTrafficSelector that = (DefaultTrafficSelector) obj;
-            return Objects.equals(selector, that.selector);
+            return Objects.equals(criteria, that.criteria);
 
         }
         return false;
     }
 
+    /**
+     * Returns a new traffic selector builder.
+     *
+     * @return traffic selector builder
+     */
+    public static TrafficSelector.Builder builder() {
+        return new Builder();
+    }
 
+    /**
+     * Returns a new traffic selector builder primed to produce entities
+     * patterned after the supplied selector.
+     *
+     * @return traffic selector builder
+     */
+    public static TrafficSelector.Builder builder(TrafficSelector selector) {
+        return new Builder(selector);
+    }
 
-    public static class Builder implements TrafficSelector.Builder {
+    /**
+     * Builder of traffic selector entities.
+     */
+    public static final class Builder implements TrafficSelector.Builder {
 
-        private final Logger log = getLogger(getClass());
+        private final Map<Criterion.Type, Criterion> selector = new HashMap<>();
 
-        private final Set<Criterion> selector = new HashSet<>();
+        private Builder() {
+        }
+
+        private Builder(TrafficSelector selector) {
+            for (Criterion c : selector.criteria()) {
+                add(c);
+            }
+        }
 
         @Override
         public Builder add(Criterion criterion) {
-            selector.add(criterion);
+            selector.put(criterion.type(), criterion);
             return this;
         }
 
@@ -107,7 +141,7 @@
 
         @Override
         public TrafficSelector build() {
-            return new DefaultTrafficSelector(selector);
+            return new DefaultTrafficSelector(ImmutableSet.copyOf(selector.values()));
         }
 
     }
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficTreatment.java b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficTreatment.java
index 2ce233f..3f43598 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficTreatment.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/DefaultTrafficTreatment.java
@@ -1,11 +1,5 @@
 package org.onlab.onos.net.flow;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
-import java.util.Collections;
-import java.util.LinkedList;
-import java.util.List;
-
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.flow.instructions.Instruction;
 import org.onlab.onos.net.flow.instructions.Instructions;
@@ -14,10 +8,24 @@
 import org.onlab.packet.VlanId;
 import org.slf4j.Logger;
 
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Default traffic treatment implementation.
+ */
 public final class DefaultTrafficTreatment implements TrafficTreatment {
 
     private final List<Instruction> instructions;
 
+    /**
+     * Creates a new traffic treatment from the specified list of instructions.
+     *
+     * @param instructions treatment instructions
+     */
     private DefaultTrafficTreatment(List<Instruction> instructions) {
         this.instructions = Collections.unmodifiableList(instructions);
     }
@@ -28,12 +36,19 @@
     }
 
     /**
+     * Returns a new traffic treatment builder.
+     *
+     * @return traffic treatment builder
+     */
+    public static TrafficTreatment.Builder builder() {
+        return new Builder();
+    }
+
+    /**
      * Builds a list of treatments following the following order.
      * Modifications -> Group -> Output (including drop)
-     *
      */
-
-    public static class Builder implements TrafficTreatment.Builder {
+    public static final class Builder implements TrafficTreatment.Builder {
 
         private final Logger log = getLogger(getClass());
 
@@ -47,27 +62,31 @@
         // TODO: should be a list of instructions based on modification objects
         List<Instruction> modifications = new LinkedList<>();
 
+        // Creates a new builder
+        private Builder() {
+        }
+
         public Builder add(Instruction instruction) {
             if (drop) {
                 return this;
             }
             switch (instruction.type()) {
-            case DROP:
-                drop = true;
-                break;
-            case OUTPUT:
-                outputs.add(instruction);
-                break;
-            case L2MODIFICATION:
-            case L3MODIFICATION:
-                // TODO: enforce modification order if any
-                modifications.add(instruction);
-                break;
-            case GROUP:
-                groups.add(instruction);
-                break;
-            default:
-                log.warn("Unknown instruction type {}", instruction.type());
+                case DROP:
+                    drop = true;
+                    break;
+                case OUTPUT:
+                    outputs.add(instruction);
+                    break;
+                case L2MODIFICATION:
+                case L3MODIFICATION:
+                    // TODO: enforce modification order if any
+                    modifications.add(instruction);
+                    break;
+                case GROUP:
+                    groups.add(instruction);
+                    break;
+                default:
+                    log.warn("Unknown instruction type {}", instruction.type());
             }
             return this;
         }
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/BatchOperation.java b/core/api/src/main/java/org/onlab/onos/net/intent/BatchOperation.java
index ad34a2c..5d0cbb8 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/BatchOperation.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/BatchOperation.java
@@ -1,20 +1,20 @@
 package org.onlab.onos.net.intent;
 //TODO is this the right package?
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 /**
  * A list of BatchOperationEntry.
  *
  * @param <T> the enum of operators <br>
- *        This enum must be defined in each sub-classes.
- *
+ *            This enum must be defined in each sub-classes.
  */
 public abstract class BatchOperation<T extends BatchOperationEntry<?, ?>> {
+
     private List<T> ops;
 
     /**
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/ConnectivityIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/ConnectivityIntent.java
index 629a9d1..70cec58 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/ConnectivityIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/ConnectivityIntent.java
@@ -1,11 +1,10 @@
 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
+import com.google.common.base.Objects;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.Objects;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Abstraction of connectivity intent for traffic matching some criteria.
@@ -26,17 +25,18 @@
 
     /**
      * Creates a connectivity intent that matches on the specified intent
-     * and applies the specified action.
+     * and applies the specified treatement.
      *
-     * @param id    intent identifier
-     * @param match traffic match
-     * @param action action
-     * @throws NullPointerException if the match or action is null
+     * @param intentId   intent identifier
+     * @param selector   traffic selector
+     * @param treatement treatement
+     * @throws NullPointerException if the selector or treatement is null
      */
-    protected ConnectivityIntent(IntentId id, TrafficSelector match, TrafficTreatment action) {
-        super(id);
-        this.selector = checkNotNull(match);
-        this.treatment = checkNotNull(action);
+    protected ConnectivityIntent(IntentId intentId, TrafficSelector selector,
+                                 TrafficTreatment treatement) {
+        super(intentId);
+        this.selector = checkNotNull(selector);
+        this.treatment = checkNotNull(treatement);
     }
 
     /**
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/HostToHostIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/HostToHostIntent.java
new file mode 100644
index 0000000..08063f0
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/HostToHostIntent.java
@@ -0,0 +1,89 @@
+package org.onlab.onos.net.intent;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Abstraction of end-station to end-station connectivity.
+ */
+public class HostToHostIntent extends ConnectivityIntent {
+
+    private final HostId src;
+    private final HostId dst;
+
+    /**
+     * Creates a new point-to-point intent with the supplied ingress/egress
+     * ports.
+     *
+     * @param intentId  intent identifier
+     * @param selector  action
+     * @param treatment ingress port
+     * @throws NullPointerException if {@code ingressPort} or {@code egressPort}
+     *                              is null.
+     */
+    public HostToHostIntent(IntentId intentId, HostId src, HostId dst,
+                            TrafficSelector selector, TrafficTreatment treatment) {
+        super(intentId, selector, treatment);
+        this.src = checkNotNull(src);
+        this.dst = checkNotNull(dst);
+    }
+
+    /**
+     * Returns the port on which the ingress traffic should be connected to the
+     * egress.
+     *
+     * @return ingress port
+     */
+    public HostId getSrc() {
+        return src;
+    }
+
+    /**
+     * Returns the port on which the traffic should egress.
+     *
+     * @return egress port
+     */
+    public HostId getDst() {
+        return dst;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        if (!super.equals(o)) {
+            return false;
+        }
+
+        HostToHostIntent that = (HostToHostIntent) o;
+        return Objects.equals(this.src, that.src)
+                && Objects.equals(this.dst, that.dst);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), src, dst);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("id", getId())
+                .add("selector", getTrafficSelector())
+                .add("treatmetn", getTrafficTreatment())
+                .add("src", src)
+                .add("dst", dst)
+                .toString();
+    }
+
+}
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/Intent.java b/core/api/src/main/java/org/onlab/onos/net/intent/Intent.java
index b239ede..d4c630a 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/Intent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/Intent.java
@@ -2,7 +2,7 @@
 
 /**
  * Abstraction of an application level intent.
- *
+ * <p/>
  * Make sure that an Intent should be immutable when a new type is defined.
  */
 public interface Intent extends BatchOperationTarget {
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentEvent.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentEvent.java
index 27ae834..c98e788 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/IntentEvent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/IntentEvent.java
@@ -1,17 +1,19 @@
 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkNotNull;
+import com.google.common.base.MoreObjects;
+import org.onlab.onos.event.AbstractEvent;
 
 import java.util.Objects;
 
-import com.google.common.base.MoreObjects;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * A class to represent an intent related event.
  */
-public class IntentEvent {
+public class IntentEvent extends AbstractEvent<IntentState, Intent> {
 
-    // TODO: determine a suitable parent class; if one does not exist, consider introducing one
+    // TODO: determine a suitable parent class; if one does not exist, consider
+    // introducing one
 
     private final long time;
     private final Intent intent;
@@ -21,13 +23,14 @@
     /**
      * Creates an event describing a state change of an intent.
      *
-     * @param intent subject intent
-     * @param state new intent state
+     * @param intent   subject intent
+     * @param state    new intent state
      * @param previous previous intent state
-     * @param time time the event created in milliseconds since start of epoch
+     * @param time     time the event created in milliseconds since start of epoch
      * @throws NullPointerException if the intent or state is null
      */
     public IntentEvent(Intent intent, IntentState state, IntentState previous, long time) {
+        super(state, intent);
         this.intent = checkNotNull(intent);
         this.state = checkNotNull(state);
         this.previous = previous;
@@ -35,16 +38,6 @@
     }
 
     /**
-     * Constructor for serializer.
-     */
-    protected IntentEvent() {
-        this.intent = null;
-        this.state = null;
-        this.previous = null;
-        this.time = 0;
-    }
-
-    /**
      * Returns the state of the intent which caused the event.
      *
      * @return the state of the intent
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentEventListener.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentEventListener.java
deleted file mode 100644
index f59ecfc..0000000
--- a/core/api/src/main/java/org/onlab/onos/net/intent/IntentEventListener.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package org.onlab.onos.net.intent;
-
-/**
- * Listener for {@link IntentEvent intent events}.
- */
-public interface IntentEventListener {
-    /**
-     * Processes the specified intent event.
-     *
-     * @param event the event to process
-     */
-    void event(IntentEvent event);
-}
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentException.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentException.java
index 4148dea..fff55be 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/IntentException.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/IntentException.java
@@ -26,7 +26,7 @@
      * Constructs an exception with the specified message and the underlying cause.
      *
      * @param message the message describing the specific nature of the error
-     * @param cause the underlying cause of this error
+     * @param cause   the underlying cause of this error
      */
     public IntentException(String message, Throwable cause) {
         super(message, cause);
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentExtensionService.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentExtensionService.java
index c6338a7f..8deb372 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/IntentExtensionService.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/IntentExtensionService.java
@@ -10,9 +10,9 @@
     /**
      * Registers the specified compiler for the given intent class.
      *
-     * @param cls intent class
+     * @param cls      intent class
      * @param compiler intent compiler
-     * @param <T> the type of intent
+     * @param <T>      the type of intent
      */
     <T extends Intent> void registerCompiler(Class<T> cls, IntentCompiler<T> compiler);
 
@@ -34,9 +34,9 @@
     /**
      * Registers the specified installer for the given installable intent class.
      *
-     * @param cls installable intent class
+     * @param cls       installable intent class
      * @param installer intent installer
-     * @param <T> the type of installable intent
+     * @param <T>       the type of installable intent
      */
     <T extends InstallableIntent> void registerInstaller(Class<T> cls, IntentInstaller<T> installer);
 
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentId.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentId.java
index 798e00c..8f132c0 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/IntentId.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/IntentId.java
@@ -2,7 +2,7 @@
 
 /**
  * Intent identifier suitable as an external key.
- *
+ * <p/>
  * This class is immutable.
  */
 public final class IntentId implements BatchOperationTarget {
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentListener.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentListener.java
new file mode 100644
index 0000000..c00c1f6
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/IntentListener.java
@@ -0,0 +1,9 @@
+package org.onlab.onos.net.intent;
+
+import org.onlab.onos.event.EventListener;
+
+/**
+ * Listener for {@link IntentEvent intent events}.
+ */
+public interface IntentListener extends EventListener<IntentEvent> {
+}
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentService.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentService.java
index 2b4fb59..c3aae54 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/IntentService.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/IntentService.java
@@ -1,6 +1,5 @@
 package org.onlab.onos.net.intent;
 
-import java.util.Set;
 
 /**
  * Service for application submitting or withdrawing their intents.
@@ -8,9 +7,9 @@
 public interface IntentService {
     /**
      * Submits an intent into the system.
-     *
-     * This is an asynchronous request meaning that any compiling
-     * or installation activities may be done at later time.
+     * <p/>
+     * This is an asynchronous request meaning that any compiling or
+     * installation activities may be done at later time.
      *
      * @param intent intent to be submitted
      */
@@ -18,9 +17,9 @@
 
     /**
      * Withdraws an intent from the system.
-     *
-     * This is an asynchronous request meaning that the environment
-     * may be affected at later time.
+     * <p/>
+     * This is an asynchronous request meaning that the environment may be
+     * affected at later time.
      *
      * @param intent intent to be withdrawn
      */
@@ -29,20 +28,27 @@
     /**
      * Submits a batch of submit &amp; withdraw operations. Such a batch is
      * assumed to be processed together.
-     *
-     * This is an asynchronous request meaning that the environment
-     * may be affected at later time.
+     * <p/>
+     * This is an asynchronous request meaning that the environment may be
+     * affected at later time.
      *
      * @param operations batch of intent operations
      */
     void execute(IntentOperations operations);
 
     /**
-     * Returns immutable set of intents currently in the system.
+     * Returns an iterable of intents currently in the system.
      *
      * @return set of intents
      */
-    Set<Intent> getIntents();
+    Iterable<Intent> getIntents();
+
+    /**
+     * Returns the number of intents currently in the system.
+     *
+     * @return number of intents
+     */
+    long getIntentCount();
 
     /**
      * Retrieves the intent specified by its identifier.
@@ -56,7 +62,8 @@
      * Retrieves the state of an intent by its identifier.
      *
      * @param id intent identifier
-     * @return the intent state or null if one with the given identifier is not found
+     * @return the intent state or null if one with the given identifier is not
+     * found
      */
     IntentState getIntentState(IntentId id);
 
@@ -65,12 +72,12 @@
      *
      * @param listener listener to be added
      */
-    void addListener(IntentEventListener listener);
+    void addListener(IntentListener listener);
 
     /**
      * Removes the specified listener for intent events.
      *
      * @param listener listener to be removed
      */
-    void removeListener(IntentEventListener listener);
+    void removeListener(IntentListener listener);
 }
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentStore.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentStore.java
new file mode 100644
index 0000000..037f179
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/IntentStore.java
@@ -0,0 +1,96 @@
+package org.onlab.onos.net.intent;
+
+import org.onlab.onos.store.Store;
+
+import java.util.List;
+
+/**
+ * Manages inventory of end-station intents; not intended for direct use.
+ */
+public interface IntentStore extends Store<IntentEvent, IntentStoreDelegate> {
+
+    /**
+     * Creates a new intent.
+     *
+     * @param intent intent
+     * @return appropriate event or null if no change resulted
+     */
+    IntentEvent createIntent(Intent intent);
+
+    /**
+     * Removes the specified intent from the inventory.
+     *
+     * @param intentId intent identification
+     * @return removed state transition event or null if intent was not found
+     */
+    IntentEvent removeIntent(IntentId intentId);
+
+    /**
+     * Returns the number of intents in the store.
+     */
+    long getIntentCount();
+
+    /**
+     * Returns a collection of all intents in the store.
+     *
+     * @return iterable collection of all intents
+     */
+    Iterable<Intent> getIntents();
+
+    /**
+     * Returns the intent with the specified identifer.
+     *
+     * @param intentId intent identification
+     * @return intent or null if not found
+     */
+    Intent getIntent(IntentId intentId);
+
+    /**
+     * Returns the state of the specified intent.
+     *
+     * @param intentId intent identification
+     * @return current intent state
+     */
+    IntentState getIntentState(IntentId intentId);
+
+    /**
+     * Sets the state of the specified intent to the new state.
+     *
+     * @param intent   intent whose state is to be changed
+     * @param newState new state
+     * @return state transition event
+     */
+    IntentEvent setState(Intent intent, IntentState newState);
+
+    /**
+     * Adds the installable intents which resulted from compilation of the
+     * specified original intent.
+     *
+     * @param intentId           original intent identifier
+     * @param installableIntents compiled installable intents
+     * @return compiled state transition event
+     */
+    IntentEvent addInstallableIntents(IntentId intentId,
+                                      List<InstallableIntent> installableIntents);
+
+    /**
+     * Returns the list of the installable events associated with the specified
+     * original intent.
+     *
+     * @param intentId original intent identifier
+     * @return compiled installable intents
+     */
+    List<InstallableIntent> getInstallableIntents(IntentId intentId);
+
+    // TODO: this should be triggered from with the store as a result of removeIntent call
+
+    /**
+     * Removes any installable intents which resulted from compilation of the
+     * specified original intent.
+     *
+     * @param intentId original intent identifier
+     * @return compiled state transition event
+     */
+    void removeInstalledIntents(IntentId intentId);
+
+}
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/IntentStoreDelegate.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentStoreDelegate.java
new file mode 100644
index 0000000..6c37db8
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/IntentStoreDelegate.java
@@ -0,0 +1,9 @@
+package org.onlab.onos.net.intent;
+
+import org.onlab.onos.store.StoreDelegate;
+
+/**
+ * Intent store delegate abstraction.
+ */
+public interface IntentStoreDelegate extends StoreDelegate<IntentEvent> {
+}
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/MultiPointToSinglePointIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/MultiPointToSinglePointIntent.java
index 1e421ab..af1e84b 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/MultiPointToSinglePointIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/MultiPointToSinglePointIntent.java
@@ -30,18 +30,20 @@
      * @param action       action
      * @param ingressPorts set of ports from which ingress traffic originates
      * @param egressPort   port to which traffic will egress
-     * @throws NullPointerException if {@code ingressPorts} or
-     * {@code egressPort} is null.
+     * @throws NullPointerException     if {@code ingressPorts} or
+     *                                  {@code egressPort} is null.
      * @throws IllegalArgumentException if the size of {@code ingressPorts} is
-     * not more than 1
+     *                                  not more than 1
      */
-    public MultiPointToSinglePointIntent(IntentId id, TrafficSelector match, TrafficTreatment action,
-            Set<ConnectPoint> ingressPorts, ConnectPoint egressPort) {
+    public MultiPointToSinglePointIntent(IntentId id, TrafficSelector match,
+                                         TrafficTreatment action,
+                                         Set<ConnectPoint> ingressPorts,
+                                         ConnectPoint egressPort) {
         super(id, match, action);
 
         checkNotNull(ingressPorts);
         checkArgument(!ingressPorts.isEmpty(),
-                "there should be at least one ingress port");
+                      "there should be at least one ingress port");
 
         this.ingressPorts = Sets.newHashSet(ingressPorts);
         this.egressPort = checkNotNull(egressPort);
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/OpticalConnectivityIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/OpticalConnectivityIntent.java
index d11dc7c..b99eb70 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/OpticalConnectivityIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/OpticalConnectivityIntent.java
@@ -3,30 +3,30 @@
 import org.onlab.onos.net.ConnectPoint;
 
 // TODO: consider if this intent should be sub-class of ConnectivityIntent
+
 /**
  * An optical layer Intent for a connectivity from a transponder port to another
  * transponder port.
- * <p>
+ * <p/>
  * This class doesn't accepts lambda specifier. This class computes path between
  * ports and assign lambda automatically. The lambda can be specified using
  * OpticalPathFlow class.
  */
 public class OpticalConnectivityIntent extends AbstractIntent {
-    protected ConnectPoint srcConnectPoint;
-    protected ConnectPoint dstConnectPoint;
+    protected ConnectPoint src;
+    protected ConnectPoint dst;
 
     /**
      * Constructor.
      *
-     * @param id ID for this new Intent object.
-     * @param srcConnectPoint The source transponder port.
-     * @param dstConnectPoint The destination transponder port.
+     * @param id  ID for this new Intent object.
+     * @param src The source transponder port.
+     * @param dst The destination transponder port.
      */
-    public OpticalConnectivityIntent(IntentId id,
-            ConnectPoint srcConnectPoint, ConnectPoint dstConnectPoint) {
+    public OpticalConnectivityIntent(IntentId id, ConnectPoint src, ConnectPoint dst) {
         super(id);
-        this.srcConnectPoint = srcConnectPoint;
-        this.dstConnectPoint = dstConnectPoint;
+        this.src = src;
+        this.dst = dst;
     }
 
     /**
@@ -34,8 +34,8 @@
      */
     protected OpticalConnectivityIntent() {
         super();
-        this.srcConnectPoint = null;
-        this.dstConnectPoint = null;
+        this.src = null;
+        this.dst = null;
     }
 
     /**
@@ -44,7 +44,7 @@
      * @return The source transponder port.
      */
     public ConnectPoint getSrcConnectPoint() {
-        return srcConnectPoint;
+        return src;
     }
 
     /**
@@ -52,7 +52,7 @@
      *
      * @return The source transponder port.
      */
-    public ConnectPoint getDstConnectPoint() {
-        return dstConnectPoint;
+    public ConnectPoint getDst() {
+        return dst;
     }
 }
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/PathIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/PathIntent.java
index 39ad011..6809ce2 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/PathIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/PathIntent.java
@@ -12,7 +12,7 @@
 /**
  * Abstraction of explicitly path specified connectivity intent.
  */
-public class PathIntent extends PointToPointIntent {
+public class PathIntent extends PointToPointIntent implements InstallableIntent {
 
     private final Path path;
 
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/PointToPointIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/PointToPointIntent.java
index b1d18ee..4c86bae 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/PointToPointIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/PointToPointIntent.java
@@ -1,14 +1,13 @@
 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Objects;
-
+import com.google.common.base.MoreObjects;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.MoreObjects;
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Abstraction of point-to-point connectivity.
@@ -23,15 +22,17 @@
      * ports.
      *
      * @param id          intent identifier
-     * @param match       traffic match
-     * @param action      action
+     * @param selector    traffic selector
+     * @param treatment   treatment
      * @param ingressPort ingress port
      * @param egressPort  egress port
      * @throws NullPointerException if {@code ingressPort} or {@code egressPort} is null.
      */
-    public PointToPointIntent(IntentId id, TrafficSelector match, TrafficTreatment action,
-                              ConnectPoint ingressPort, ConnectPoint egressPort) {
-        super(id, match, action);
+    public PointToPointIntent(IntentId id, TrafficSelector selector,
+                              TrafficTreatment treatment,
+                              ConnectPoint ingressPort,
+                              ConnectPoint egressPort) {
+        super(id, selector, treatment);
         this.ingressPort = checkNotNull(ingressPort);
         this.egressPort = checkNotNull(egressPort);
     }
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/SinglePointToMultiPointIntent.java b/core/api/src/main/java/org/onlab/onos/net/intent/SinglePointToMultiPointIntent.java
index e69a740..af2616b 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/SinglePointToMultiPointIntent.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/SinglePointToMultiPointIntent.java
@@ -1,17 +1,16 @@
 package org.onlab.onos.net.intent;
 
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import java.util.Objects;
-import java.util.Set;
-
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.Sets;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.flow.TrafficSelector;
 import org.onlab.onos.net.flow.TrafficTreatment;
 
-import com.google.common.base.MoreObjects;
-import com.google.common.collect.Sets;
+import java.util.Objects;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * Abstraction of single source, multiple destination connectivity intent.
@@ -25,23 +24,24 @@
      * Creates a new single-to-multi point connectivity intent.
      *
      * @param id          intent identifier
-     * @param match       traffic match
-     * @param action      action
+     * @param selector    traffic selector
+     * @param treatment   treatment
      * @param ingressPort port on which traffic will ingress
      * @param egressPorts set of ports on which traffic will egress
-     * @throws NullPointerException if {@code ingressPort} or
-     * {@code egressPorts} is null
+     * @throws NullPointerException     if {@code ingressPort} or
+     *                                  {@code egressPorts} is null
      * @throws IllegalArgumentException if the size of {@code egressPorts} is
-     * not more than 1
+     *                                  not more than 1
      */
-    public SinglePointToMultiPointIntent(IntentId id, TrafficSelector match, TrafficTreatment action,
+    public SinglePointToMultiPointIntent(IntentId id, TrafficSelector selector,
+                                         TrafficTreatment treatment,
                                          ConnectPoint ingressPort,
                                          Set<ConnectPoint> egressPorts) {
-        super(id, match, action);
+        super(id, selector, treatment);
 
         checkNotNull(egressPorts);
         checkArgument(!egressPorts.isEmpty(),
-                "there should be at least one egress port");
+                      "there should be at least one egress port");
 
         this.ingressPort = checkNotNull(ingressPort);
         this.egressPorts = Sets.newHashSet(egressPorts);
diff --git a/core/api/src/main/java/org/onlab/onos/net/intent/package-info.java b/core/api/src/main/java/org/onlab/onos/net/intent/package-info.java
index e1e6782..2517067 100644
--- a/core/api/src/main/java/org/onlab/onos/net/intent/package-info.java
+++ b/core/api/src/main/java/org/onlab/onos/net/intent/package-info.java
@@ -1,5 +1,8 @@
 /**
- * Intent Package. TODO
+ * Set of abstractions for conveying high-level intents for treatment of
+ * selected network traffic by allowing applications to express the
+ * <em>what</em> rather than the <em>how</em>. This makes such instructions
+ * largely independent of topology and device specifics, thus allowing them to
+ * survive topology mutations.
  */
-
 package org.onlab.onos.net.intent;
\ No newline at end of file
diff --git a/core/api/src/main/java/org/onlab/onos/net/packet/DefaultPacketContext.java b/core/api/src/main/java/org/onlab/onos/net/packet/DefaultPacketContext.java
index 6f1b708..75100c6 100644
--- a/core/api/src/main/java/org/onlab/onos/net/packet/DefaultPacketContext.java
+++ b/core/api/src/main/java/org/onlab/onos/net/packet/DefaultPacketContext.java
@@ -24,7 +24,7 @@
         this.inPkt = inPkt;
         this.outPkt = outPkt;
         this.block = new AtomicBoolean(block);
-        this.builder = new DefaultTrafficTreatment.Builder();
+        this.builder = DefaultTrafficTreatment.builder();
     }
 
     @Override
diff --git a/core/api/src/main/java/org/onlab/onos/net/provider/ProviderId.java b/core/api/src/main/java/org/onlab/onos/net/provider/ProviderId.java
index afaecbe..c2a3133 100644
--- a/core/api/src/main/java/org/onlab/onos/net/provider/ProviderId.java
+++ b/core/api/src/main/java/org/onlab/onos/net/provider/ProviderId.java
@@ -3,6 +3,7 @@
 import java.util.Objects;
 
 import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * External identity of a {@link org.onlab.onos.net.provider.Provider} family.
@@ -19,10 +20,22 @@
  */
 public class ProviderId {
 
+    /**
+     * Represents no provider ID.
+     */
+    public static final ProviderId NONE = new ProviderId();
+
     private final String scheme;
     private final String id;
     private final boolean ancillary;
 
+    // For serialization
+    private ProviderId() {
+        scheme = null;
+        id = null;
+        ancillary = false;
+    }
+
     /**
      * Creates a new primary provider identifier from the specified string.
      * The providers are expected to follow the reverse DNS convention, e.g.
@@ -45,8 +58,8 @@
      * @param ancillary ancillary provider indicator
      */
     public ProviderId(String scheme, String id, boolean ancillary) {
-        this.scheme = scheme;
-        this.id = id;
+        this.scheme = checkNotNull(scheme, "Scheme cannot be null");
+        this.id = checkNotNull(id, "ID cannot be null");
         this.ancillary = ancillary;
     }
 
diff --git a/core/api/src/main/java/org/onlab/onos/store/ClockProviderService.java b/core/api/src/main/java/org/onlab/onos/store/ClockProviderService.java
new file mode 100644
index 0000000..759b62a
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/store/ClockProviderService.java
@@ -0,0 +1,19 @@
+package org.onlab.onos.store;
+
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+
+//TODO: Consider renaming to DeviceClockProviderService?
+/**
+* Interface for feeding term information to a logical clock service
+* that vends per device timestamps.
+*/
+public interface ClockProviderService {
+
+    /**
+     * Updates the mastership term for the specified deviceId.
+     * @param deviceId device identifier.
+     * @param term mastership term.
+     */
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term);
+}
diff --git a/core/api/src/main/java/org/onlab/onos/store/ClockService.java b/core/api/src/main/java/org/onlab/onos/store/ClockService.java
index 2446ab7..20549e8 100644
--- a/core/api/src/main/java/org/onlab/onos/store/ClockService.java
+++ b/core/api/src/main/java/org/onlab/onos/store/ClockService.java
@@ -1,6 +1,5 @@
 package org.onlab.onos.store;
 
-import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.net.DeviceId;
 
 // TODO: Consider renaming to DeviceClockService?
@@ -15,12 +14,4 @@
      * @return timestamp.
      */
     public Timestamp getTimestamp(DeviceId deviceId);
-
-    // TODO: Should this be here or separate as Admin service, etc.?
-    /**
-     * Updates the mastership term for the specified deviceId.
-     * @param deviceId device identifier.
-     * @param term mastership term.
-     */
-    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term);
 }
diff --git a/core/api/src/main/java/org/onlab/onos/store/Timestamp.java b/core/api/src/main/java/org/onlab/onos/store/Timestamp.java
index b9d3648..b3caf85 100644
--- a/core/api/src/main/java/org/onlab/onos/store/Timestamp.java
+++ b/core/api/src/main/java/org/onlab/onos/store/Timestamp.java
@@ -2,7 +2,15 @@
 
 /**
  * Opaque version structure.
+ * <p>
+ * Classes implementing this interface must also implement
+ * {@link #hashCode()} and {@link #equals(Object)}.
  */
 public interface Timestamp extends Comparable<Timestamp> {
 
+    @Override
+    public abstract int hashCode();
+
+    @Override
+    public abstract boolean equals(Object obj);
 }
diff --git a/core/api/src/test/java/org/onlab/onos/net/intent/ConnectivityIntentTest.java b/core/api/src/test/java/org/onlab/onos/net/intent/ConnectivityIntentTest.java
index fb1efee..10a0069 100644
--- a/core/api/src/test/java/org/onlab/onos/net/intent/ConnectivityIntentTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/intent/ConnectivityIntentTest.java
@@ -16,8 +16,8 @@
 public abstract class ConnectivityIntentTest extends IntentTest {
 
     public static final IntentId IID = new IntentId(123);
-    public static final TrafficSelector MATCH = (new DefaultTrafficSelector.Builder()).build();
-    public static final TrafficTreatment NOP = (new DefaultTrafficTreatment.Builder()).build();
+    public static final TrafficSelector MATCH = DefaultTrafficSelector.builder().build();
+    public static final TrafficTreatment NOP = DefaultTrafficTreatment.builder().build();
 
     public static final ConnectPoint P1 = new ConnectPoint(DeviceId.deviceId("111"), PortNumber.portNumber(0x1));
     public static final ConnectPoint P2 = new ConnectPoint(DeviceId.deviceId("222"), PortNumber.portNumber(0x2));
diff --git a/core/api/src/test/java/org/onlab/onos/net/intent/FakeIntentManager.java b/core/api/src/test/java/org/onlab/onos/net/intent/FakeIntentManager.java
index df46ec5..349749e 100644
--- a/core/api/src/test/java/org/onlab/onos/net/intent/FakeIntentManager.java
+++ b/core/api/src/test/java/org/onlab/onos/net/intent/FakeIntentManager.java
@@ -11,19 +11,19 @@
 import java.util.concurrent.Executors;
 
 /**
- * Fake implementation of the intent service to assist in developing tests
- * of the interface contract.
+ * Fake implementation of the intent service to assist in developing tests of
+ * the interface contract.
  */
 public class FakeIntentManager implements TestableIntentService {
 
     private final Map<IntentId, Intent> intents = new HashMap<>();
     private final Map<IntentId, IntentState> intentStates = new HashMap<>();
     private final Map<IntentId, List<InstallableIntent>> installables = new HashMap<>();
-    private final Set<IntentEventListener> listeners = new HashSet<>();
+    private final Set<IntentListener> listeners = new HashSet<>();
 
     private final Map<Class<? extends Intent>, IntentCompiler<? extends Intent>> compilers = new HashMap<>();
-    private final Map<Class<? extends InstallableIntent>,
-            IntentInstaller<? extends InstallableIntent>> installers = new HashMap<>();
+    private final Map<Class<? extends InstallableIntent>, IntentInstaller<? extends InstallableIntent>> installers
+        = new HashMap<>();
 
     private final ExecutorService executor = Executors.newSingleThreadExecutor();
     private final List<IntentException> exceptions = new ArrayList<>();
@@ -76,7 +76,8 @@
 
     private <T extends InstallableIntent> IntentInstaller<T> getInstaller(T intent) {
         @SuppressWarnings("unchecked")
-        IntentInstaller<T> installer = (IntentInstaller<T>) installers.get(intent.getClass());
+        IntentInstaller<T> installer = (IntentInstaller<T>) installers.get(intent
+                .getClass());
         if (installer == null) {
             throw new IntentException("no installer for class " + intent.getClass());
         }
@@ -125,7 +126,6 @@
         }
     }
 
-
     // Sets the internal state for the given intent and dispatches an event
     private void setState(Intent intent, IntentState state) {
         IntentState previous = intentStates.get(intent.getId());
@@ -175,6 +175,11 @@
     }
 
     @Override
+    public long getIntentCount() {
+        return intents.size();
+    }
+
+    @Override
     public Intent getIntent(IntentId id) {
         return intents.get(id);
     }
@@ -185,23 +190,24 @@
     }
 
     @Override
-    public void addListener(IntentEventListener listener) {
+    public void addListener(IntentListener listener) {
         listeners.add(listener);
     }
 
     @Override
-    public void removeListener(IntentEventListener listener) {
+    public void removeListener(IntentListener listener) {
         listeners.remove(listener);
     }
 
     private void dispatch(IntentEvent event) {
-        for (IntentEventListener listener : listeners) {
+        for (IntentListener listener : listeners) {
             listener.event(event);
         }
     }
 
     @Override
-    public <T extends Intent> void registerCompiler(Class<T> cls, IntentCompiler<T> compiler) {
+    public <T extends Intent> void registerCompiler(Class<T> cls,
+            IntentCompiler<T> compiler) {
         compilers.put(cls, compiler);
     }
 
@@ -216,7 +222,8 @@
     }
 
     @Override
-    public <T extends InstallableIntent> void registerInstaller(Class<T> cls, IntentInstaller<T> installer) {
+    public <T extends InstallableIntent> void registerInstaller(Class<T> cls,
+            IntentInstaller<T> installer) {
         installers.put(cls, installer);
     }
 
@@ -227,7 +234,7 @@
 
     @Override
     public Map<Class<? extends InstallableIntent>,
-            IntentInstaller<? extends InstallableIntent>> getInstallers() {
+    IntentInstaller<? extends InstallableIntent>> getInstallers() {
         return Collections.unmodifiableMap(installers);
     }
 
@@ -252,7 +259,8 @@
         if (!installers.containsKey(intent.getClass())) {
             Class<?> cls = intent.getClass();
             while (cls != Object.class) {
-                // As long as we're within the InstallableIntent class descendants
+                // As long as we're within the InstallableIntent class
+                // descendants
                 if (InstallableIntent.class.isAssignableFrom(cls)) {
                     IntentInstaller<?> installer = installers.get(cls);
                     if (installer != null) {
diff --git a/core/api/src/test/java/org/onlab/onos/net/intent/IntentServiceTest.java b/core/api/src/test/java/org/onlab/onos/net/intent/IntentServiceTest.java
index c7682b1..825be86 100644
--- a/core/api/src/test/java/org/onlab/onos/net/intent/IntentServiceTest.java
+++ b/core/api/src/test/java/org/onlab/onos/net/intent/IntentServiceTest.java
@@ -51,7 +51,7 @@
     @Test
     public void basics() {
         // Make sure there are no intents
-        assertEquals("incorrect intent count", 0, service.getIntents().size());
+        assertEquals("incorrect intent count", 0, service.getIntentCount());
 
         // Register a compiler and an installer both setup for success.
         service.registerCompiler(TestIntent.class, new TestCompiler(new TestInstallableIntent(INSTALLABLE_IID)));
@@ -73,8 +73,7 @@
         validateEvents(intent, SUBMITTED, COMPILED, INSTALLED);
 
         // Make sure there is just one intent (and is ours)
-        assertEquals("incorrect intent count", 1, service.getIntents().size());
-        assertEquals("incorrect intent", intent, service.getIntent(intent.getId()));
+        assertEquals("incorrect intent count", 1, service.getIntentCount());
 
         // Reset the listener events
         listener.events.clear();
@@ -250,7 +249,7 @@
 
 
     // Fixture to track emitted intent events
-    protected class TestListener implements IntentEventListener {
+    protected class TestListener implements IntentListener {
         final List<IntentEvent> events = new ArrayList<>();
 
         @Override
diff --git a/core/net/src/main/java/org/onlab/onos/net/device/impl/DeviceManager.java b/core/net/src/main/java/org/onlab/onos/net/device/impl/DeviceManager.java
index b61afd2..3c4a885 100644
--- a/core/net/src/main/java/org/onlab/onos/net/device/impl/DeviceManager.java
+++ b/core/net/src/main/java/org/onlab/onos/net/device/impl/DeviceManager.java
@@ -38,7 +38,7 @@
 import org.onlab.onos.net.device.PortDescription;
 import org.onlab.onos.net.provider.AbstractProviderRegistry;
 import org.onlab.onos.net.provider.AbstractProviderService;
-import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.ClockProviderService;
 import org.slf4j.Logger;
 
 /**
@@ -80,7 +80,7 @@
     protected MastershipTermService termService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected ClockService clockService;
+    protected ClockProviderService clockProviderService;
 
     @Activate
     public void activate() {
@@ -274,7 +274,7 @@
             if (event.master().equals(clusterService.getLocalNode().id())) {
                 MastershipTerm term = mastershipService.requestTermService()
                         .getMastershipTerm(event.subject());
-                clockService.setMastershipTerm(event.subject(), term);
+                clockProviderService.setMastershipTerm(event.subject(), term);
                 applyRole(event.subject(), MastershipRole.MASTER);
             } else {
                 applyRole(event.subject(), MastershipRole.STANDBY);
diff --git a/core/net/src/main/java/org/onlab/onos/net/flow/impl/FlowRuleManager.java b/core/net/src/main/java/org/onlab/onos/net/flow/impl/FlowRuleManager.java
index 00619b3..db82eed 100644
--- a/core/net/src/main/java/org/onlab/onos/net/flow/impl/FlowRuleManager.java
+++ b/core/net/src/main/java/org/onlab/onos/net/flow/impl/FlowRuleManager.java
@@ -242,15 +242,16 @@
         }
 
         private boolean checkRuleLiveness(FlowRule swRule, FlowRule storedRule) {
-            int timeout = storedRule.timeout();
-            if (storedRule.packets() != swRule.packets()) {
-                deadRounds.get(swRule).set(0);
-                return true;
-            }
-
-            return (deadRounds.get(swRule).getAndIncrement() *
-                    FlowRuleProvider.POLL_INTERVAL) <= timeout;
-
+            return true;
+//            int timeout = storedRule.timeout();
+//            if (storedRule.packets() != swRule.packets()) {
+//                deadRounds.get(swRule).set(0);
+//                return true;
+//            }
+//
+//            return (deadRounds.get(swRule).getAndIncrement() *
+//                    FlowRuleProvider.POLL_INTERVAL) <= timeout;
+//
         }
 
         // Posts the specified event to the local event dispatcher.
diff --git a/core/net/src/main/java/org/onlab/onos/net/host/impl/HostMonitor.java b/core/net/src/main/java/org/onlab/onos/net/host/impl/HostMonitor.java
index 9f8dd48..628f424 100644
--- a/core/net/src/main/java/org/onlab/onos/net/host/impl/HostMonitor.java
+++ b/core/net/src/main/java/org/onlab/onos/net/host/impl/HostMonitor.java
@@ -4,9 +4,9 @@
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.TimeUnit;
 
 import org.jboss.netty.util.Timeout;
@@ -59,15 +59,14 @@
 
     private final Set<IpAddress> monitoredAddresses;
 
-    private final Map<ProviderId, HostProvider> hostProviders;
+    private final ConcurrentMap<ProviderId, HostProvider> hostProviders;
 
-    private final long probeRate;
+    private static final long DEFAULT_PROBE_RATE = 30000; // milliseconds
+    private long probeRate = DEFAULT_PROBE_RATE;
 
     private final Timeout timeout;
 
-    public HostMonitor(
-            DeviceService deviceService,
-            PacketService packetService,
+    public HostMonitor(DeviceService deviceService, PacketService packetService,
             HostManager hostService) {
 
         this.deviceService = deviceService;
@@ -77,15 +76,7 @@
         monitoredAddresses = new HashSet<>();
         hostProviders = new ConcurrentHashMap<>();
 
-        probeRate = 30000; // milliseconds
-
         timeout = Timer.getTimer().newTimeout(this, 0, TimeUnit.MILLISECONDS);
-
-        addDefaultAddresses();
-    }
-
-    private void addDefaultAddresses() {
-        //monitoredAddresses.add(IpAddress.valueOf("10.0.0.1"));
     }
 
     void addMonitoringFor(IpAddress ip) {
@@ -104,10 +95,6 @@
         hostProviders.put(provider.id(), provider);
     }
 
-    void unregisterHostProvider(HostProvider provider) {
-        // TODO find out how to call this
-    }
-
     @Override
     public void run(Timeout timeout) throws Exception {
         for (IpAddress ip : monitoredAddresses) {
@@ -121,7 +108,9 @@
             } else {
                 for (Host host : hosts) {
                     HostProvider provider = hostProviders.get(host.providerId());
-                    if (provider != null) {
+                    if (provider == null) {
+                        hostProviders.remove(host.providerId(), null);
+                    } else {
                         provider.triggerProbe(host);
                     }
                 }
@@ -161,7 +150,7 @@
         List<Instruction> instructions = new ArrayList<>();
         instructions.add(Instructions.createOutput(port.number()));
 
-        TrafficTreatment treatment = new DefaultTrafficTreatment.Builder()
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder()
         .setOutput(port.number())
         .build();
 
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/AbstractBlockAllocatorBasedIdGenerator.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/AbstractBlockAllocatorBasedIdGenerator.java
new file mode 100644
index 0000000..00b64da
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/AbstractBlockAllocatorBasedIdGenerator.java
@@ -0,0 +1,42 @@
+package org.onlab.onos.net.intent.impl;
+
+import org.onlab.onos.net.intent.IdGenerator;
+
+/**
+ * Base class of {@link IdGenerator} implementations which use {@link IdBlockAllocator} as
+ * backend.
+ *
+ * @param <T> the type of ID
+ */
+public abstract class AbstractBlockAllocatorBasedIdGenerator<T> implements IdGenerator<T> {
+    protected final IdBlockAllocator allocator;
+    protected IdBlock idBlock;
+
+    /**
+     * Constructs an ID generator which use {@link IdBlockAllocator} as backend.
+     *
+     * @param allocator
+     */
+    protected AbstractBlockAllocatorBasedIdGenerator(IdBlockAllocator allocator) {
+        this.allocator = allocator;
+        this.idBlock = allocator.allocateUniqueIdBlock();
+    }
+
+    @Override
+    public synchronized T getNewId() {
+        try {
+            return convertFrom(idBlock.getNextId());
+        } catch (UnavailableIdException e) {
+            idBlock = allocator.allocateUniqueIdBlock();
+            return convertFrom(idBlock.getNextId());
+        }
+    }
+
+    /**
+     * Returns an ID instance of {@code T} type from the long value.
+     *
+     * @param value original long value
+     * @return ID instance
+     */
+    protected abstract T convertFrom(long value);
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/DummyIdBlockAllocator.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/DummyIdBlockAllocator.java
new file mode 100644
index 0000000..f331aa2
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/DummyIdBlockAllocator.java
@@ -0,0 +1,31 @@
+package org.onlab.onos.net.intent.impl;
+
+public class DummyIdBlockAllocator implements IdBlockAllocator {
+    private long blockTop;
+    private static final long BLOCK_SIZE = 0x1000000L;
+
+    /**
+     * Returns a block of IDs which are unique and unused.
+     * Range of IDs is fixed size and is assigned incrementally as this method
+     * called.
+     *
+     * @return an IdBlock containing a set of unique IDs
+     */
+    @Override
+    public IdBlock allocateUniqueIdBlock() {
+        synchronized (this)  {
+            long blockHead = blockTop;
+            long blockTail = blockTop + BLOCK_SIZE;
+
+            IdBlock block = new IdBlock(blockHead, BLOCK_SIZE);
+            blockTop = blockTail;
+
+            return block;
+        }
+    }
+
+    @Override
+    public IdBlock allocateUniqueIdBlock(long range) {
+        throw new UnsupportedOperationException("Not supported yet");
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/HostToHostIntentCompiler.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/HostToHostIntentCompiler.java
new file mode 100644
index 0000000..a8bea2e
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/HostToHostIntentCompiler.java
@@ -0,0 +1,67 @@
+package org.onlab.onos.net.intent.impl;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.intent.HostToHostIntent;
+import org.onlab.onos.net.intent.IdGenerator;
+import org.onlab.onos.net.intent.Intent;
+import org.onlab.onos.net.intent.IntentCompiler;
+import org.onlab.onos.net.intent.IntentExtensionService;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.PathIntent;
+import org.onlab.onos.net.topology.PathService;
+
+/**
+ * A intent compiler for {@link HostToHostIntent}.
+ */
+@Component(immediate = true)
+public class HostToHostIntentCompiler
+        implements IntentCompiler<HostToHostIntent> {
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentExtensionService intentManager;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected PathService pathService;
+
+    private IdGenerator<IntentId> intentIdGenerator;
+
+    @Activate
+    public void activate() {
+        IdBlockAllocator idBlockAllocator = new DummyIdBlockAllocator();
+        intentIdGenerator = new IdBlockAllocatorBasedIntentIdGenerator(idBlockAllocator);
+        intentManager.registerCompiler(HostToHostIntent.class, this);
+    }
+
+    @Deactivate
+    public void deactivate() {
+        intentManager.unregisterCompiler(HostToHostIntent.class);
+    }
+
+    @Override
+    public List<Intent> compile(HostToHostIntent intent) {
+        Set<Path> paths = pathService.getPaths(intent.getSrc(), intent.getDst());
+        if (paths.isEmpty()) {
+            throw new PathNotFoundException();
+        }
+        Path path = paths.iterator().next();
+
+        return Arrays.asList((Intent) new PathIntent(
+                intentIdGenerator.getNewId(),
+                intent.getTrafficSelector(),
+                intent.getTrafficTreatment(),
+                new ConnectPoint(intent.getSrc(), PortNumber.ALL),
+                new ConnectPoint(intent.getDst(), PortNumber.ALL),
+                path));
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlock.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlock.java
new file mode 100644
index 0000000..ce418ea
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlock.java
@@ -0,0 +1,111 @@
+package org.onlab.onos.net.intent.impl;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicLong;
+
+import com.google.common.base.MoreObjects;
+
+/**
+ * A class representing an ID space.
+ */
+public final class IdBlock {
+    private final long start;
+    private final long size;
+
+    private final AtomicLong currentId;
+
+    /**
+     * Constructs a new ID block with the specified size and initial value.
+     *
+     * @param start initial value of the block
+     * @param size size of the block
+     * @throws IllegalArgumentException if the size is less than or equal to 0
+     */
+    public IdBlock(long start, long size) {
+        checkArgument(size > 0, "size should be more than 0, but %s", size);
+
+        this.start = start;
+        this.size = size;
+
+        this.currentId = new AtomicLong(start);
+    }
+
+    // TODO: consider if this method is needed or not
+    /**
+     * Returns the initial value.
+     *
+     * @return initial value
+     */
+    public long getStart() {
+        return start;
+    }
+
+    // TODO: consider if this method is needed or not
+    /**
+     * Returns the last value.
+     *
+     * @return last value
+     */
+    public long getEnd() {
+        return start + size - 1;
+    }
+
+    /**
+     * Returns the block size.
+     *
+     * @return block size
+     */
+    public long getSize() {
+        return size;
+    }
+
+    /**
+     * Returns the next ID in the block.
+     *
+     * @return next ID
+     * @throws UnavailableIdException if there is no available ID in the block.
+     */
+    public long getNextId() {
+        final long id = currentId.getAndIncrement();
+        if (id > getEnd()) {
+            throw new UnavailableIdException(String.format(
+                    "used all IDs in allocated space (size: %d, end: %d, current: %d)",
+                    size, getEnd(), id
+            ));
+        }
+
+        return id;
+    }
+
+    // TODO: Do we really need equals and hashCode? Should it contain currentId?
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        IdBlock that = (IdBlock) o;
+        return Objects.equals(this.start, that.start)
+                && Objects.equals(this.size, that.size)
+                && Objects.equals(this.currentId.get(), that.currentId.get());
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(start, size, currentId);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("start", start)
+                .add("size", size)
+                .add("currentId", currentId)
+                .toString();
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlockAllocator.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlockAllocator.java
new file mode 100644
index 0000000..1adac02
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlockAllocator.java
@@ -0,0 +1,21 @@
+package org.onlab.onos.net.intent.impl;
+
+/**
+ * An interface that gives unique ID spaces.
+ */
+public interface IdBlockAllocator {
+    /**
+     * Allocates a unique Id Block.
+     *
+     * @return Id Block.
+     */
+    IdBlock allocateUniqueIdBlock();
+
+    /**
+     * Allocates next unique id and retrieve a new range of ids if needed.
+     *
+     * @param range range to use for the identifier
+     * @return Id Block.
+     */
+    IdBlock allocateUniqueIdBlock(long range);
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlockAllocatorBasedIntentIdGenerator.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlockAllocatorBasedIntentIdGenerator.java
new file mode 100644
index 0000000..9620e59
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IdBlockAllocatorBasedIntentIdGenerator.java
@@ -0,0 +1,25 @@
+package org.onlab.onos.net.intent.impl;
+
+import org.onlab.onos.net.intent.IntentId;
+
+/**
+ * An implementation of {@link org.onlab.onos.net.intent.IdGenerator} of intent ID,
+ * which uses {@link IdBlockAllocator}.
+ */
+public class IdBlockAllocatorBasedIntentIdGenerator extends AbstractBlockAllocatorBasedIdGenerator<IntentId> {
+
+    /**
+     * Constructs an intent ID generator, which uses the specified ID block allocator
+     * to generate a global unique intent ID.
+     *
+     * @param allocator the ID block allocator to use for generating intent IDs
+     */
+    public IdBlockAllocatorBasedIntentIdGenerator(IdBlockAllocator allocator) {
+        super(allocator);
+    }
+
+    @Override
+    protected IntentId convertFrom(long value) {
+        return new IntentId(value);
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentCompilationException.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentCompilationException.java
new file mode 100644
index 0000000..bf739df
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentCompilationException.java
@@ -0,0 +1,22 @@
+package org.onlab.onos.net.intent.impl;
+
+import org.onlab.onos.net.intent.IntentException;
+
+/**
+ * An exception thrown when a intent compilation fails.
+ */
+public class IntentCompilationException extends IntentException {
+    private static final long serialVersionUID = 235237603018210810L;
+
+    public IntentCompilationException() {
+        super();
+    }
+
+    public IntentCompilationException(String message) {
+        super(message);
+    }
+
+    public IntentCompilationException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentInstallationException.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentInstallationException.java
new file mode 100644
index 0000000..3b17cf1
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentInstallationException.java
@@ -0,0 +1,22 @@
+package org.onlab.onos.net.intent.impl;
+
+import org.onlab.onos.net.intent.IntentException;
+
+/**
+ * An exception thrown when intent installation fails.
+ */
+public class IntentInstallationException extends IntentException {
+    private static final long serialVersionUID = 3720268258616014168L;
+
+    public IntentInstallationException() {
+        super();
+    }
+
+    public IntentInstallationException(String message) {
+        super(message);
+    }
+
+    public IntentInstallationException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentManager.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentManager.java
new file mode 100644
index 0000000..f1c9de3
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentManager.java
@@ -0,0 +1,363 @@
+package org.onlab.onos.net.intent.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.onos.net.intent.IntentState.FAILED;
+import static org.onlab.onos.net.intent.IntentState.INSTALLED;
+import static org.onlab.onos.net.intent.IntentState.WITHDRAWING;
+import static org.onlab.onos.net.intent.IntentState.WITHDRAWN;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.event.AbstractListenerRegistry;
+import org.onlab.onos.event.EventDeliveryService;
+import org.onlab.onos.net.intent.InstallableIntent;
+import org.onlab.onos.net.intent.Intent;
+import org.onlab.onos.net.intent.IntentCompiler;
+import org.onlab.onos.net.intent.IntentEvent;
+import org.onlab.onos.net.intent.IntentException;
+import org.onlab.onos.net.intent.IntentExtensionService;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.IntentInstaller;
+import org.onlab.onos.net.intent.IntentListener;
+import org.onlab.onos.net.intent.IntentOperations;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.intent.IntentState;
+import org.onlab.onos.net.intent.IntentStore;
+import org.onlab.onos.net.intent.IntentStoreDelegate;
+import org.slf4j.Logger;
+
+import com.google.common.collect.ImmutableMap;
+
+/**
+ * An implementation of Intent Manager.
+ */
+@Component(immediate = true)
+@Service
+public class IntentManager
+        implements IntentService, IntentExtensionService {
+    private final Logger log = getLogger(getClass());
+
+    public static final String INTENT_NULL = "Intent cannot be null";
+    public static final String INTENT_ID_NULL = "Intent ID cannot be null";
+
+    // Collections for compiler, installer, and listener are ONOS instance local
+    private final ConcurrentMap<Class<? extends Intent>,
+            IntentCompiler<? extends Intent>> compilers = new ConcurrentHashMap<>();
+    private final ConcurrentMap<Class<? extends InstallableIntent>,
+            IntentInstaller<? extends InstallableIntent>> installers = new ConcurrentHashMap<>();
+    private final CopyOnWriteArrayList<IntentListener> listeners = new CopyOnWriteArrayList<>();
+
+    private final AbstractListenerRegistry<IntentEvent, IntentListener>
+        listenerRegistry = new AbstractListenerRegistry<>();
+
+    private final IntentStoreDelegate delegate = new InternalStoreDelegate();
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentStore store;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected EventDeliveryService eventDispatcher;
+
+    @Activate
+    public void activate() {
+        store.setDelegate(delegate);
+        eventDispatcher.addSink(IntentEvent.class, listenerRegistry);
+
+//        this.intentEvents = new IntentMap<>("intentState", IntentEvent.class, collectionsService);
+//        this.installableIntents =
+//                new IntentMap<>("installableIntents", IntentCompilationResult.class, collectionsService);
+//
+//
+//        this.intentEvents.addListener(new InternalEntryListener(new InternalIntentEventListener()));
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        store.unsetDelegate(delegate);
+        eventDispatcher.removeSink(IntentEvent.class);
+        log.info("Stopped");
+    }
+
+    @Override
+    public void submit(Intent intent) {
+        checkNotNull(intent, INTENT_NULL);
+        registerSubclassCompilerIfNeeded(intent);
+        IntentEvent event = store.createIntent(intent);
+        eventDispatcher.post(event);
+        processStoreEvent(event);
+    }
+
+    @Override
+    public void withdraw(Intent intent) {
+        checkNotNull(intent, INTENT_NULL);
+        IntentEvent event = store.setState(intent, WITHDRAWING);
+        eventDispatcher.post(event);
+        processStoreEvent(event);
+    }
+
+    // FIXME: implement this method
+    @Override
+    public void execute(IntentOperations operations) {
+        throw new UnsupportedOperationException("execute() is not implemented yet");
+    }
+
+    @Override
+    public Iterable<Intent> getIntents() {
+        return store.getIntents();
+    }
+
+    @Override
+    public long getIntentCount() {
+        return store.getIntentCount();
+    }
+
+    @Override
+    public Intent getIntent(IntentId id) {
+        checkNotNull(id, INTENT_ID_NULL);
+        return store.getIntent(id);
+    }
+
+    @Override
+    public IntentState getIntentState(IntentId id) {
+        checkNotNull(id, INTENT_ID_NULL);
+        return store.getIntentState(id);
+    }
+
+    @Override
+    public void addListener(IntentListener listener) {
+        listenerRegistry.addListener(listener);
+    }
+
+    @Override
+    public void removeListener(IntentListener listener) {
+        listenerRegistry.removeListener(listener);
+    }
+
+    @Override
+    public <T extends Intent> void registerCompiler(Class<T> cls, IntentCompiler<T> compiler) {
+        compilers.put(cls, compiler);
+    }
+
+    @Override
+    public <T extends Intent> void unregisterCompiler(Class<T> cls) {
+        compilers.remove(cls);
+    }
+
+    @Override
+    public Map<Class<? extends Intent>, IntentCompiler<? extends Intent>> getCompilers() {
+        return ImmutableMap.copyOf(compilers);
+    }
+
+    @Override
+    public <T extends InstallableIntent> void registerInstaller(Class<T> cls, IntentInstaller<T> installer) {
+        installers.put(cls, installer);
+    }
+
+    @Override
+    public <T extends InstallableIntent> void unregisterInstaller(Class<T> cls) {
+        installers.remove(cls);
+    }
+
+    @Override
+    public Map<Class<? extends InstallableIntent>, IntentInstaller<? extends InstallableIntent>> getInstallers() {
+        return ImmutableMap.copyOf(installers);
+    }
+
+    /**
+     * Invokes all of registered intent event listener.
+     *
+     * @param event event supplied to a listener as an argument
+     */
+    private void invokeListeners(IntentEvent event) {
+        for (IntentListener listener : listeners) {
+            listener.event(event);
+        }
+    }
+
+    /**
+     * Returns the corresponding intent compiler to the specified intent.
+     *
+     * @param intent intent
+     * @param <T> the type of intent
+     * @return intent compiler corresponding to the specified intent
+     */
+    private <T extends Intent> IntentCompiler<T> getCompiler(T intent) {
+        @SuppressWarnings("unchecked")
+        IntentCompiler<T> compiler = (IntentCompiler<T>) compilers.get(intent.getClass());
+        if (compiler == null) {
+            throw new IntentException("no compiler for class " + intent.getClass());
+        }
+        return compiler;
+    }
+
+    /**
+     * Returns the corresponding intent installer to the specified installable intent.
+     * @param intent intent
+     * @param <T> the type of installable intent
+     * @return intent installer corresponding to the specified installable intent
+     */
+    private <T extends InstallableIntent> IntentInstaller<T> getInstaller(T intent) {
+        @SuppressWarnings("unchecked")
+        IntentInstaller<T> installer = (IntentInstaller<T>) installers.get(intent.getClass());
+        if (installer == null) {
+            throw new IntentException("no installer for class " + intent.getClass());
+        }
+        return installer;
+    }
+
+    /**
+     * Compiles an intent.
+     *
+     * @param intent intent
+     */
+    private void compileIntent(Intent intent) {
+        // FIXME: To make SDN-IP workable ASAP, only single level compilation is implemented
+        // TODO: implement compilation traversing tree structure
+        List<InstallableIntent> installable = new ArrayList<>();
+        for (Intent compiled : getCompiler(intent).compile(intent)) {
+            installable.add((InstallableIntent) compiled);
+        }
+        IntentEvent event = store.addInstallableIntents(intent.getId(), installable);
+        eventDispatcher.post(event);
+        processStoreEvent(event);
+    }
+
+    /**
+     * Installs an intent.
+     *
+     * @param intent intent
+     */
+    private void installIntent(Intent intent) {
+        for (InstallableIntent installable : store.getInstallableIntents(intent.getId())) {
+            registerSubclassInstallerIfNeeded(installable);
+            getInstaller(installable).install(installable);
+        }
+
+        IntentEvent event = store.setState(intent, INSTALLED);
+        eventDispatcher.post(event);
+        processStoreEvent(event);
+
+    }
+
+    /**
+     * Uninstalls an intent.
+     *
+     * @param intent intent
+     */
+    private void uninstallIntent(Intent intent) {
+        for (InstallableIntent installable : store.getInstallableIntents(intent.getId())) {
+            getInstaller(installable).uninstall(installable);
+        }
+
+        store.removeInstalledIntents(intent.getId());
+        store.setState(intent, WITHDRAWN);
+    }
+
+    /**
+     * Registers an intent compiler of the specified intent if an intent compiler
+     * for the intent is not registered. This method traverses the class hierarchy of
+     * the intent. Once an intent compiler for a parent type is found, this method
+     * registers the found intent compiler.
+     *
+     * @param intent intent
+     */
+    private void registerSubclassCompilerIfNeeded(Intent intent) {
+        if (!compilers.containsKey(intent.getClass())) {
+            Class<?> cls = intent.getClass();
+            while (cls != Object.class) {
+                // As long as we're within the Intent class descendants
+                if (Intent.class.isAssignableFrom(cls)) {
+                    IntentCompiler<?> compiler = compilers.get(cls);
+                    if (compiler != null) {
+                        compilers.put(intent.getClass(), compiler);
+                        return;
+                    }
+                }
+                cls = cls.getSuperclass();
+            }
+        }
+    }
+
+    /**
+     * Registers an intent installer of the specified intent if an intent installer
+     * for the intent is not registered. This method traverses the class hierarchy of
+     * the intent. Once an intent installer for a parent type is found, this method
+     * registers the found intent installer.
+     *
+     * @param intent intent
+     */
+    private void registerSubclassInstallerIfNeeded(InstallableIntent intent) {
+        if (!installers.containsKey(intent.getClass())) {
+            Class<?> cls = intent.getClass();
+            while (cls != Object.class) {
+                // As long as we're within the InstallableIntent class descendants
+                if (InstallableIntent.class.isAssignableFrom(cls)) {
+                    IntentInstaller<?> installer = installers.get(cls);
+                    if (installer != null) {
+                        installers.put(intent.getClass(), installer);
+                        return;
+                    }
+                }
+                cls = cls.getSuperclass();
+            }
+        }
+    }
+
+    /**
+     * Handles state transition of submitted intents.
+     */
+    private void processStoreEvent(IntentEvent event) {
+            invokeListeners(event);
+            Intent intent = event.getIntent();
+
+            try {
+                switch (event.getState()) {
+                    case SUBMITTED:
+                        compileIntent(intent);
+                        break;
+                    case COMPILED:
+                        installIntent(intent);
+                        break;
+                    case INSTALLED:
+                        break;
+                    case WITHDRAWING:
+                        uninstallIntent(intent);
+                        break;
+                    case WITHDRAWN:
+                        break;
+                    case FAILED:
+                        break;
+                    default:
+                        throw new IllegalStateException(
+                                "the state of IntentEvent is illegal: " + event.getState());
+                }
+            } catch (IntentException e) {
+                store.setState(intent, FAILED);
+            }
+
+    }
+
+    // Store delegate to re-post events emitted from the store.
+    private class InternalStoreDelegate implements IntentStoreDelegate {
+        @Override
+        public void notify(IntentEvent event) {
+            processStoreEvent(event);
+            eventDispatcher.post(event);
+        }
+    }
+
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentRemovalException.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentRemovalException.java
new file mode 100644
index 0000000..5ee4ee4
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/IntentRemovalException.java
@@ -0,0 +1,22 @@
+package org.onlab.onos.net.intent.impl;
+
+import org.onlab.onos.net.intent.IntentException;
+
+/**
+ * An exception thrown when intent removal failed.
+ */
+public class IntentRemovalException extends IntentException {
+    private static final long serialVersionUID = -5259226322037891951L;
+
+    public IntentRemovalException() {
+        super();
+    }
+
+    public IntentRemovalException(String message) {
+        super(message);
+    }
+
+    public IntentRemovalException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathIntentInstaller.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathIntentInstaller.java
new file mode 100644
index 0000000..6aa9f66
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathIntentInstaller.java
@@ -0,0 +1,75 @@
+package org.onlab.onos.net.intent.impl;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.onlab.onos.ApplicationId;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.flow.DefaultFlowRule;
+import org.onlab.onos.net.flow.DefaultTrafficSelector;
+import org.onlab.onos.net.flow.DefaultTrafficTreatment;
+import org.onlab.onos.net.flow.FlowRule;
+import org.onlab.onos.net.flow.FlowRuleService;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.intent.IntentExtensionService;
+import org.onlab.onos.net.intent.IntentInstaller;
+import org.onlab.onos.net.intent.PathIntent;
+
+import java.util.Iterator;
+
+/**
+ * Installer for {@link PathIntent path connectivity intents}.
+ */
+@Component(immediate = true)
+public class PathIntentInstaller implements IntentInstaller<PathIntent> {
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected IntentExtensionService intentManager;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected FlowRuleService flowRuleService;
+
+    private final ApplicationId appId = ApplicationId.getAppId();
+
+    @Activate
+    public void activate() {
+        intentManager.registerInstaller(PathIntent.class, this);
+    }
+
+    @Deactivate
+    public void deactivate() {
+        intentManager.unregisterInstaller(PathIntent.class);
+    }
+
+    @Override
+    public void install(PathIntent intent) {
+        TrafficSelector.Builder builder =
+                DefaultTrafficSelector.builder(intent.getTrafficSelector());
+        Iterator<Link> links = intent.getPath().links().iterator();
+        ConnectPoint prev = links.next().dst();
+        while (links.hasNext()) {
+            builder.matchInport(prev.port());
+            Link link = links.next();
+
+            TrafficTreatment.Builder treat = DefaultTrafficTreatment.builder();
+            treat.setOutput(link.src().port());
+
+            FlowRule rule = new DefaultFlowRule(link.src().deviceId(),
+                                                builder.build(), treat.build(),
+                                                0, appId, 30);
+            flowRuleService.applyFlowRules(rule);
+
+            prev = link.dst();
+        }
+
+    }
+
+    @Override
+    public void uninstall(PathIntent intent) {
+        //TODO
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathNotFoundException.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathNotFoundException.java
new file mode 100644
index 0000000..a1fd63a
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/PathNotFoundException.java
@@ -0,0 +1,22 @@
+package org.onlab.onos.net.intent.impl;
+
+import org.onlab.onos.net.intent.IntentException;
+
+/**
+ * An exception thrown when a path is not found.
+ */
+public class PathNotFoundException extends IntentException {
+    private static final long serialVersionUID = -2087045731049914733L;
+
+    public PathNotFoundException() {
+        super();
+    }
+
+    public PathNotFoundException(String message) {
+        super(message);
+    }
+
+    public PathNotFoundException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/UnavailableIdException.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/UnavailableIdException.java
new file mode 100644
index 0000000..fd4f122
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/UnavailableIdException.java
@@ -0,0 +1,34 @@
+package org.onlab.onos.net.intent.impl;
+
+/**
+ * Represents that there is no available IDs.
+ */
+public class UnavailableIdException extends RuntimeException {
+
+    private static final long serialVersionUID = -2287403908433720122L;
+
+    /**
+     * Constructs an exception with no message and no underlying cause.
+     */
+    public UnavailableIdException() {
+    }
+
+    /**
+     * Constructs an exception with the specified message.
+     *
+     * @param message the message describing the specific nature of the error
+     */
+    public UnavailableIdException(String message) {
+        super(message);
+    }
+
+    /**
+     * Constructs an exception with the specified message and the underlying cause.
+     *
+     * @param message the message describing the specific nature of the error
+     * @param cause the underlying cause of this error
+     */
+    public UnavailableIdException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/core/net/src/main/java/org/onlab/onos/net/intent/impl/package-info.java b/core/net/src/main/java/org/onlab/onos/net/intent/impl/package-info.java
new file mode 100644
index 0000000..3f00271
--- /dev/null
+++ b/core/net/src/main/java/org/onlab/onos/net/intent/impl/package-info.java
@@ -0,0 +1,5 @@
+/**
+ * Core subsystem for tracking high-level intents for treatment of selected
+ * network traffic.
+ */
+package org.onlab.onos.net.intent.impl;
\ No newline at end of file
diff --git a/core/net/src/main/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManager.java b/core/net/src/main/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManager.java
index 6e07c3e..3570948 100644
--- a/core/net/src/main/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManager.java
+++ b/core/net/src/main/java/org/onlab/onos/net/proxyarp/impl/ProxyArpManager.java
@@ -43,7 +43,6 @@
 import com.google.common.collect.Lists;
 import com.google.common.collect.Multimap;
 
-
 @Component(immediate = true)
 @Service
 public class ProxyArpManager implements ProxyArpService {
@@ -128,7 +127,7 @@
 
         Ethernet arpReply = buildArpReply(dst, eth);
         // TODO: check send status with host service.
-        TrafficTreatment.Builder builder = new DefaultTrafficTreatment.Builder();
+        TrafficTreatment.Builder builder = DefaultTrafficTreatment.builder();
         builder.setOutput(src.location().port());
         packetService.emit(new DefaultOutboundPacket(src.location().deviceId(),
                 builder.build(), ByteBuffer.wrap(arpReply.serialize())));
@@ -148,7 +147,7 @@
         if (h == null) {
             flood(eth);
         } else {
-            TrafficTreatment.Builder builder = new DefaultTrafficTreatment.Builder();
+            TrafficTreatment.Builder builder = DefaultTrafficTreatment.builder();
             builder.setOutput(h.location().port());
             packetService.emit(new DefaultOutboundPacket(h.location().deviceId(),
                     builder.build(), ByteBuffer.wrap(eth.serialize())));
@@ -166,7 +165,7 @@
 
         synchronized (externalPorts) {
             for (Entry<Device, PortNumber> entry : externalPorts.entries()) {
-                builder = new DefaultTrafficTreatment.Builder();
+                builder = DefaultTrafficTreatment.builder();
                 builder.setOutput(entry.getValue());
                 packetService.emit(new DefaultOutboundPacket(entry.getKey().id(),
                         builder.build(), buf));
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/cluster/impl/MessageSerializer.java b/core/store/dist/src/main/java/org/onlab/onos/store/cluster/impl/MessageSerializer.java
index 98e80f7..10368aa 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/cluster/impl/MessageSerializer.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/cluster/impl/MessageSerializer.java
@@ -1,46 +1,16 @@
 package org.onlab.onos.store.cluster.impl;
 
-import de.javakaffee.kryoserializers.URISerializer;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Service;
-import org.onlab.onos.cluster.ControllerNode;
-import org.onlab.onos.cluster.DefaultControllerNode;
-import org.onlab.onos.cluster.NodeId;
-import org.onlab.onos.net.ConnectPoint;
-import org.onlab.onos.net.DefaultDevice;
-import org.onlab.onos.net.DefaultLink;
-import org.onlab.onos.net.DefaultPort;
-import org.onlab.onos.net.Device;
-import org.onlab.onos.net.DeviceId;
-import org.onlab.onos.net.Element;
-import org.onlab.onos.net.Link;
-import org.onlab.onos.net.LinkKey;
-import org.onlab.onos.net.MastershipRole;
-import org.onlab.onos.net.Port;
-import org.onlab.onos.net.PortNumber;
-import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.onos.store.cluster.messaging.MessageSubject;
 import org.onlab.onos.store.cluster.messaging.SerializationService;
-import org.onlab.onos.store.serializers.ConnectPointSerializer;
-import org.onlab.onos.store.serializers.DefaultLinkSerializer;
-import org.onlab.onos.store.serializers.DefaultPortSerializer;
-import org.onlab.onos.store.serializers.DeviceIdSerializer;
-import org.onlab.onos.store.serializers.IpPrefixSerializer;
-import org.onlab.onos.store.serializers.LinkKeySerializer;
-import org.onlab.onos.store.serializers.NodeIdSerializer;
-import org.onlab.onos.store.serializers.PortNumberSerializer;
-import org.onlab.onos.store.serializers.ProviderIdSerializer;
-import org.onlab.packet.IpPrefix;
+import org.onlab.onos.store.serializers.KryoPoolUtil;
 import org.onlab.util.KryoPool;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.net.URI;
-import java.util.ArrayList;
-import java.util.HashMap;
-
 /**
  * Factory for parsing messages sent between cluster members.
  */
@@ -72,34 +42,10 @@
      * Sets up the common serialzers pool.
      */
     protected void setupKryoPool() {
-        // FIXME Slice out types used in common to separate pool/namespace.
         serializerPool = KryoPool.newBuilder()
-                .register(ArrayList.class,
-                          HashMap.class,
-
-                          ControllerNode.State.class,
-                          Device.Type.class,
-
-                          DefaultControllerNode.class,
-                          DefaultDevice.class,
-                          MastershipRole.class,
-                          Port.class,
-                          Element.class,
-
-                          Link.Type.class,
-
-                          MessageSubject.class
-                )
-                .register(IpPrefix.class, new IpPrefixSerializer())
-                .register(URI.class, new URISerializer())
-                .register(NodeId.class, new NodeIdSerializer())
-                .register(ProviderId.class, new ProviderIdSerializer())
-                .register(DeviceId.class, new DeviceIdSerializer())
-                .register(PortNumber.class, new PortNumberSerializer())
-                .register(DefaultPort.class, new DefaultPortSerializer())
-                .register(LinkKey.class, new LinkKeySerializer())
-                .register(ConnectPoint.class, new ConnectPointSerializer())
-                .register(DefaultLink.class, new DefaultLinkSerializer())
+                .register(KryoPoolUtil.API)
+                // TODO: Should MessageSubject be in API bundle?
+                .register(MessageSubject.class)
                 .build()
                 .populate(1);
     }
@@ -114,4 +60,4 @@
     public byte[] encode(Object payload) {
         return serializerPool.serialize(payload);
     }
-}
\ No newline at end of file
+}
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/cluster/messaging/impl/package-info.java b/core/store/dist/src/main/java/org/onlab/onos/store/cluster/messaging/impl/package-info.java
new file mode 100644
index 0000000..6c1e71b
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/cluster/messaging/impl/package-info.java
@@ -0,0 +1,4 @@
+/**
+ * Implementation of the cluster messaging mechanism.
+ */
+package org.onlab.onos.store.cluster.messaging.impl;
\ No newline at end of file
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/impl/OnosTimestamp.java b/core/store/dist/src/main/java/org/onlab/onos/store/common/impl/MastershipBasedTimestamp.java
similarity index 73%
rename from core/store/dist/src/main/java/org/onlab/onos/store/impl/OnosTimestamp.java
rename to core/store/dist/src/main/java/org/onlab/onos/store/common/impl/MastershipBasedTimestamp.java
index 2005582..0f4f894 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/impl/OnosTimestamp.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/common/impl/MastershipBasedTimestamp.java
@@ -1,4 +1,4 @@
-package org.onlab.onos.store.impl;
+package org.onlab.onos.store.common.impl;
 
 import static com.google.common.base.Preconditions.checkArgument;
 
@@ -9,12 +9,11 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.ComparisonChain;
 
-// If it is store specific, implement serializable interfaces?
 /**
  * Default implementation of Timestamp.
  * TODO: Better documentation.
  */
-public final class OnosTimestamp implements Timestamp {
+public final class MastershipBasedTimestamp implements Timestamp {
 
     private final int termNumber;
     private final int sequenceNumber;
@@ -25,15 +24,16 @@
      * @param termNumber the mastership termNumber
      * @param sequenceNumber  the sequenceNumber number within the termNumber
      */
-    public OnosTimestamp(int termNumber, int sequenceNumber) {
+    public MastershipBasedTimestamp(int termNumber, int sequenceNumber) {
         this.termNumber = termNumber;
         this.sequenceNumber = sequenceNumber;
     }
 
     @Override
     public int compareTo(Timestamp o) {
-        checkArgument(o instanceof OnosTimestamp, "Must be OnosTimestamp", o);
-        OnosTimestamp that = (OnosTimestamp) o;
+        checkArgument(o instanceof MastershipBasedTimestamp,
+                "Must be MastershipBasedTimestamp", o);
+        MastershipBasedTimestamp that = (MastershipBasedTimestamp) o;
 
         return ComparisonChain.start()
                 .compare(this.termNumber, that.termNumber)
@@ -51,10 +51,10 @@
         if (this == obj) {
             return true;
         }
-        if (!(obj instanceof OnosTimestamp)) {
+        if (!(obj instanceof MastershipBasedTimestamp)) {
             return false;
         }
-        OnosTimestamp that = (OnosTimestamp) obj;
+        MastershipBasedTimestamp that = (MastershipBasedTimestamp) obj;
         return Objects.equals(this.termNumber, that.termNumber) &&
                 Objects.equals(this.sequenceNumber, that.sequenceNumber);
     }
@@ -84,4 +84,11 @@
     public int sequenceNumber() {
         return sequenceNumber;
     }
+
+    // Default constructor for serialization
+    @Deprecated
+    protected MastershipBasedTimestamp() {
+        this.termNumber = -1;
+        this.sequenceNumber = -1;
+    }
 }
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/common/impl/Timestamped.java b/core/store/dist/src/main/java/org/onlab/onos/store/common/impl/Timestamped.java
new file mode 100644
index 0000000..2908b16
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/common/impl/Timestamped.java
@@ -0,0 +1,79 @@
+package org.onlab.onos.store.common.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Objects;
+
+import org.onlab.onos.store.Timestamp;
+
+/**
+ * Wrapper class to store Timestamped value.
+ * @param <T>
+ */
+public final class Timestamped<T> {
+
+    private final Timestamp timestamp;
+    private final T value;
+
+    /**
+     * Creates a time stamped value.
+     *
+     * @param value to be timestamp
+     * @param timestamp the timestamp
+     */
+    public Timestamped(T value, Timestamp timestamp) {
+        this.value = checkNotNull(value);
+        this.timestamp = checkNotNull(timestamp);
+    }
+
+    /**
+     * Returns the value.
+     * @return value
+     */
+    public T value() {
+        return value;
+    }
+
+    /**
+     * Returns the time stamp.
+     * @return time stamp
+     */
+    public Timestamp timestamp() {
+        return timestamp;
+    }
+
+    /**
+     * Tests if this timestamped value is newer than the other.
+     *
+     * @param other timestamped value
+     * @return true if this instance is newer.
+     */
+    public boolean isNewer(Timestamped<T> other) {
+        return this.timestamp.compareTo(checkNotNull(other).timestamp()) > 0;
+    }
+
+    @Override
+    public int hashCode() {
+        return timestamp.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof Timestamped)) {
+            return false;
+        }
+        @SuppressWarnings("unchecked")
+        Timestamped<T> that = (Timestamped<T>) obj;
+        return Objects.equals(this.timestamp, that.timestamp);
+    }
+
+    // Default constructor for serialization
+    @Deprecated
+    protected Timestamped() {
+        this.value = null;
+        this.timestamp = null;
+    }
+}
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/common/impl/package-info.java b/core/store/dist/src/main/java/org/onlab/onos/store/common/impl/package-info.java
new file mode 100644
index 0000000..992fd49
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/common/impl/package-info.java
@@ -0,0 +1,5 @@
+/**
+ * Common abstractions and facilities for implementing distributed store
+ * using gossip protocol.
+ */
+package org.onlab.onos.store.common.impl;
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/OnosClockService.java b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceClockManager.java
similarity index 81%
rename from core/store/dist/src/main/java/org/onlab/onos/store/device/impl/OnosClockService.java
rename to core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceClockManager.java
index a99482f..e1e3692 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/OnosClockService.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceClockManager.java
@@ -12,14 +12,18 @@
 import org.apache.felix.scr.annotations.Service;
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.ClockProviderService;
 import org.onlab.onos.store.ClockService;
 import org.onlab.onos.store.Timestamp;
-import org.onlab.onos.store.impl.OnosTimestamp;
+import org.onlab.onos.store.common.impl.MastershipBasedTimestamp;
 import org.slf4j.Logger;
 
+/**
+ * Clock service to issue Timestamp based on Device Mastership.
+ */
 @Component(immediate = true)
 @Service
-public class OnosClockService implements ClockService {
+public class DeviceClockManager implements ClockService, ClockProviderService {
 
     private final Logger log = getLogger(getClass());
 
@@ -43,7 +47,7 @@
         if (term == null) {
             throw new IllegalStateException("Requesting timestamp for a deviceId without mastership");
         }
-        return new OnosTimestamp(term.termNumber(), ticker.incrementAndGet());
+        return new MastershipBasedTimestamp(term.termNumber(), ticker.incrementAndGet());
     }
 
     @Override
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/GossipDeviceStore.java b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/GossipDeviceStore.java
new file mode 100644
index 0000000..0edbc21
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/GossipDeviceStore.java
@@ -0,0 +1,652 @@
+package org.onlab.onos.store.device.impl;
+
+import com.google.common.collect.FluentIterable;
+import com.google.common.collect.ImmutableList;
+
+import org.apache.commons.lang3.concurrent.ConcurrentException;
+import org.apache.commons.lang3.concurrent.ConcurrentInitializer;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.net.Annotations;
+import org.onlab.onos.net.DefaultAnnotations;
+import org.onlab.onos.net.DefaultDevice;
+import org.onlab.onos.net.DefaultPort;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.Device.Type;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.SparseAnnotations;
+import org.onlab.onos.net.device.DefaultDeviceDescription;
+import org.onlab.onos.net.device.DefaultPortDescription;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.device.DeviceEvent;
+import org.onlab.onos.net.device.DeviceStore;
+import org.onlab.onos.net.device.DeviceStoreDelegate;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.AbstractStore;
+import org.onlab.onos.store.ClockService;
+import org.onlab.onos.store.Timestamp;
+import org.onlab.onos.store.common.impl.Timestamped;
+import org.slf4j.Logger;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Objects;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Predicates.notNull;
+import static org.onlab.onos.net.device.DeviceEvent.Type.*;
+import static org.slf4j.LoggerFactory.getLogger;
+import static org.apache.commons.lang3.concurrent.ConcurrentUtils.createIfAbsentUnchecked;
+import static org.onlab.onos.net.DefaultAnnotations.merge;
+import static com.google.common.base.Verify.verify;
+
+// TODO: implement remove event handling and call *Internal
+/**
+ * Manages inventory of infrastructure devices using gossip protocol to distribute
+ * information.
+ */
+@Component(immediate = true)
+@Service
+public class GossipDeviceStore
+        extends AbstractStore<DeviceEvent, DeviceStoreDelegate>
+        implements DeviceStore {
+
+    private final Logger log = getLogger(getClass());
+
+    public static final String DEVICE_NOT_FOUND = "Device with ID %s not found";
+
+    // TODO: Check if inner Map can be replaced with plain Map
+    // innerMap is used to lock a Device, thus instance should never be replaced.
+    // collection of Description given from various providers
+    private final ConcurrentMap<DeviceId,
+                            ConcurrentMap<ProviderId, DeviceDescriptions>>
+                                deviceDescs = new ConcurrentHashMap<>();
+
+    // cache of Device and Ports generated by compositing descriptions from providers
+    private final ConcurrentMap<DeviceId, Device> devices = new ConcurrentHashMap<>();
+    private final ConcurrentMap<DeviceId, ConcurrentMap<PortNumber, Port>> devicePorts = new ConcurrentHashMap<>();
+
+    // available(=UP) devices
+    private final Set<DeviceId> availableDevices = new HashSet<>();
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ClockService clockService;
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        deviceDescs.clear();
+        devices.clear();
+        devicePorts.clear();
+        availableDevices.clear();
+        log.info("Stopped");
+    }
+
+    @Override
+    public int getDeviceCount() {
+        return devices.size();
+    }
+
+    @Override
+    public Iterable<Device> getDevices() {
+        return Collections.unmodifiableCollection(devices.values());
+    }
+
+    @Override
+    public Device getDevice(DeviceId deviceId) {
+        return devices.get(deviceId);
+    }
+
+    @Override
+    public synchronized DeviceEvent createOrUpdateDevice(ProviderId providerId, DeviceId deviceId,
+                                     DeviceDescription deviceDescription) {
+        Timestamp newTimestamp = clockService.getTimestamp(deviceId);
+        final Timestamped<DeviceDescription> deltaDesc = new Timestamped<>(deviceDescription, newTimestamp);
+        DeviceEvent event = createOrUpdateDeviceInternal(providerId, deviceId, deltaDesc);
+        if (event != null) {
+            // FIXME: broadcast deltaDesc, UP
+            log.debug("broadcast deltaDesc");
+        }
+        return event;
+    }
+
+    private DeviceEvent createOrUpdateDeviceInternal(ProviderId providerId, DeviceId deviceId,
+                Timestamped<DeviceDescription> deltaDesc) {
+
+        // Collection of DeviceDescriptions for a Device
+        ConcurrentMap<ProviderId, DeviceDescriptions> providerDescs
+            = createIfAbsentUnchecked(deviceDescs, deviceId,
+                    new InitConcurrentHashMap<ProviderId, DeviceDescriptions>());
+
+
+        DeviceDescriptions descs
+            = createIfAbsentUnchecked(providerDescs, providerId,
+                    new InitDeviceDescs(deltaDesc));
+
+        // update description
+        synchronized (providerDescs) {
+            // locking per device
+
+            final Device oldDevice = devices.get(deviceId);
+            final Device newDevice;
+
+            if (deltaDesc == descs.getDeviceDesc() ||
+                deltaDesc.isNewer(descs.getDeviceDesc())) {
+                // on new device or valid update
+                descs.putDeviceDesc(deltaDesc);
+                newDevice = composeDevice(deviceId, providerDescs);
+            } else {
+                // outdated event, ignored.
+                return null;
+            }
+            if (oldDevice == null) {
+                // ADD
+                return createDevice(providerId, newDevice);
+            } else {
+                // UPDATE or ignore (no change or stale)
+                return updateDevice(providerId, oldDevice, newDevice);
+            }
+        }
+    }
+
+    // Creates the device and returns the appropriate event if necessary.
+    // Guarded by deviceDescs value (=locking Device)
+    private DeviceEvent createDevice(ProviderId providerId,
+                                    Device newDevice) {
+
+        // update composed device cache
+        Device oldDevice = devices.putIfAbsent(newDevice.id(), newDevice);
+        verify(oldDevice == null,
+                "Unexpected Device in cache. PID:%s [old=%s, new=%s]",
+                providerId, oldDevice, newDevice);
+
+        if (!providerId.isAncillary()) {
+            availableDevices.add(newDevice.id());
+        }
+
+        return new DeviceEvent(DeviceEvent.Type.DEVICE_ADDED, newDevice, null);
+    }
+
+    // Updates the device and returns the appropriate event if necessary.
+    // Guarded by deviceDescs value (=locking Device)
+    private DeviceEvent updateDevice(ProviderId providerId,
+                                     Device oldDevice, Device newDevice) {
+
+        // We allow only certain attributes to trigger update
+        if (!Objects.equals(oldDevice.hwVersion(), newDevice.hwVersion()) ||
+            !Objects.equals(oldDevice.swVersion(), newDevice.swVersion()) ||
+            !isAnnotationsEqual(oldDevice.annotations(), newDevice.annotations())) {
+
+            boolean replaced = devices.replace(newDevice.id(), oldDevice, newDevice);
+            if (!replaced) {
+                verify(replaced,
+                        "Replacing devices cache failed. PID:%s [expected:%s, found:%s, new=%s]",
+                        providerId, oldDevice, devices.get(newDevice.id())
+                        , newDevice);
+            }
+            if (!providerId.isAncillary()) {
+                availableDevices.add(newDevice.id());
+            }
+            return new DeviceEvent(DeviceEvent.Type.DEVICE_UPDATED, newDevice, null);
+        }
+
+        // Otherwise merely attempt to change availability if primary provider
+        if (!providerId.isAncillary()) {
+            boolean added = availableDevices.add(newDevice.id());
+            return !added ? null :
+                    new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, newDevice, null);
+        }
+        return null;
+    }
+
+    @Override
+    public DeviceEvent markOffline(DeviceId deviceId) {
+        ConcurrentMap<ProviderId, DeviceDescriptions> providerDescs
+            = createIfAbsentUnchecked(deviceDescs, deviceId,
+                    new InitConcurrentHashMap<ProviderId, DeviceDescriptions>());
+
+        // locking device
+        synchronized (providerDescs) {
+            Device device = devices.get(deviceId);
+            if (device == null) {
+                return null;
+            }
+            boolean removed = availableDevices.remove(deviceId);
+            if (removed) {
+                // TODO: broadcast ... DOWN only?
+                return new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device, null);
+
+            }
+            return null;
+        }
+    }
+
+    @Override
+    public synchronized List<DeviceEvent> updatePorts(ProviderId providerId, DeviceId deviceId,
+            List<PortDescription> portDescriptions) {
+        Timestamp newTimestamp = clockService.getTimestamp(deviceId);
+
+        List<Timestamped<PortDescription>> deltaDescs = new ArrayList<>(portDescriptions.size());
+        for (PortDescription e : portDescriptions) {
+            deltaDescs.add(new Timestamped<PortDescription>(e, newTimestamp));
+        }
+
+        List<DeviceEvent> events = updatePortsInternal(providerId, deviceId, deltaDescs);
+        if (!events.isEmpty()) {
+            // FIXME: broadcast deltaDesc, UP
+            log.debug("broadcast deltaDesc");
+        }
+        return events;
+
+    }
+
+    private List<DeviceEvent> updatePortsInternal(ProviderId providerId, DeviceId deviceId,
+                List<Timestamped<PortDescription>> deltaDescs) {
+
+        Device device = devices.get(deviceId);
+        checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+
+        ConcurrentMap<ProviderId, DeviceDescriptions> descsMap = deviceDescs.get(deviceId);
+        checkArgument(descsMap != null, DEVICE_NOT_FOUND, deviceId);
+
+        DeviceDescriptions descs = descsMap.get(providerId);
+        // every provider must provide DeviceDescription.
+        checkArgument(descs != null,
+                "Device description for Device ID %s from Provider %s was not found",
+                deviceId, providerId);
+
+        List<DeviceEvent> events = new ArrayList<>();
+        synchronized (descsMap) {
+            Map<PortNumber, Port> ports = getPortMap(deviceId);
+
+            // Add new ports
+            Set<PortNumber> processed = new HashSet<>();
+            for (Timestamped<PortDescription> deltaDesc : deltaDescs) {
+                final PortNumber number = deltaDesc.value().portNumber();
+                final Port oldPort = ports.get(number);
+                final Port newPort;
+
+                final Timestamped<PortDescription> existingPortDesc = descs.getPortDesc(number);
+                if (existingPortDesc == null ||
+                    deltaDesc == existingPortDesc ||
+                    deltaDesc.isNewer(existingPortDesc)) {
+                    // on new port or valid update
+                    // update description
+                    descs.putPortDesc(deltaDesc);
+                    newPort = composePort(device, number, descsMap);
+                } else {
+                    // outdated event, ignored.
+                    continue;
+                }
+
+                events.add(oldPort == null ?
+                                   createPort(device, newPort, ports) :
+                                   updatePort(device, oldPort, newPort, ports));
+                processed.add(number);
+            }
+
+            events.addAll(pruneOldPorts(device, ports, processed));
+        }
+        return FluentIterable.from(events).filter(notNull()).toList();
+    }
+
+    // Creates a new port based on the port description adds it to the map and
+    // Returns corresponding event.
+    // Guarded by deviceDescs value (=locking Device)
+    private DeviceEvent createPort(Device device, Port newPort,
+                                   Map<PortNumber, Port> ports) {
+        ports.put(newPort.number(), newPort);
+        return new DeviceEvent(PORT_ADDED, device, newPort);
+    }
+
+    // Checks if the specified port requires update and if so, it replaces the
+    // existing entry in the map and returns corresponding event.
+    // Guarded by deviceDescs value (=locking Device)
+    private DeviceEvent updatePort(Device device, Port oldPort,
+                                   Port newPort,
+                                   Map<PortNumber, Port> ports) {
+        if (oldPort.isEnabled() != newPort.isEnabled() ||
+            !isAnnotationsEqual(oldPort.annotations(), newPort.annotations())) {
+
+            ports.put(oldPort.number(), newPort);
+            return new DeviceEvent(PORT_UPDATED, device, newPort);
+        }
+        return null;
+    }
+
+    // Prunes the specified list of ports based on which ports are in the
+    // processed list and returns list of corresponding events.
+    // Guarded by deviceDescs value (=locking Device)
+    private List<DeviceEvent> pruneOldPorts(Device device,
+                                            Map<PortNumber, Port> ports,
+                                            Set<PortNumber> processed) {
+        List<DeviceEvent> events = new ArrayList<>();
+        Iterator<PortNumber> iterator = ports.keySet().iterator();
+        while (iterator.hasNext()) {
+            PortNumber portNumber = iterator.next();
+            if (!processed.contains(portNumber)) {
+                events.add(new DeviceEvent(PORT_REMOVED, device,
+                                           ports.get(portNumber)));
+                iterator.remove();
+            }
+        }
+        return events;
+    }
+
+    // Gets the map of ports for the specified device; if one does not already
+    // exist, it creates and registers a new one.
+    private ConcurrentMap<PortNumber, Port> getPortMap(DeviceId deviceId) {
+        return createIfAbsentUnchecked(devicePorts, deviceId,
+                new InitConcurrentHashMap<PortNumber, Port>());
+    }
+
+    @Override
+    public synchronized DeviceEvent updatePortStatus(ProviderId providerId, DeviceId deviceId,
+            PortDescription portDescription) {
+        Timestamp newTimestamp = clockService.getTimestamp(deviceId);
+        final Timestamped<PortDescription> deltaDesc = new Timestamped<>(portDescription, newTimestamp);
+        DeviceEvent event = updatePortStatusInternal(providerId, deviceId, deltaDesc);
+        if (event != null) {
+            // FIXME: broadcast deltaDesc
+            log.debug("broadcast deltaDesc");
+        }
+        return event;
+    }
+
+    private DeviceEvent updatePortStatusInternal(ProviderId providerId, DeviceId deviceId,
+                Timestamped<PortDescription> deltaDesc) {
+
+        Device device = devices.get(deviceId);
+        checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
+
+        ConcurrentMap<ProviderId, DeviceDescriptions> descsMap = deviceDescs.get(deviceId);
+        checkArgument(descsMap != null, DEVICE_NOT_FOUND, deviceId);
+
+        DeviceDescriptions descs = descsMap.get(providerId);
+        // assuming all providers must to give DeviceDescription
+        checkArgument(descs != null,
+                "Device description for Device ID %s from Provider %s was not found",
+                deviceId, providerId);
+
+        synchronized (descsMap) {
+            ConcurrentMap<PortNumber, Port> ports = getPortMap(deviceId);
+            final PortNumber number = deltaDesc.value().portNumber();
+            final Port oldPort = ports.get(number);
+            final Port newPort;
+
+            final Timestamped<PortDescription> existingPortDesc = descs.getPortDesc(number);
+            if (existingPortDesc == null ||
+                deltaDesc == existingPortDesc ||
+                deltaDesc.isNewer(existingPortDesc)) {
+                // on new port or valid update
+                // update description
+                descs.putPortDesc(deltaDesc);
+                newPort = composePort(device, number, descsMap);
+            } else {
+                // outdated event, ignored.
+                return null;
+            }
+
+            if (oldPort == null) {
+                return createPort(device, newPort, ports);
+            } else {
+                return updatePort(device, oldPort, newPort, ports);
+            }
+        }
+    }
+
+    @Override
+    public List<Port> getPorts(DeviceId deviceId) {
+        Map<PortNumber, Port> ports = devicePorts.get(deviceId);
+        if (ports == null) {
+            return Collections.emptyList();
+        }
+        return ImmutableList.copyOf(ports.values());
+    }
+
+    @Override
+    public Port getPort(DeviceId deviceId, PortNumber portNumber) {
+        Map<PortNumber, Port> ports = devicePorts.get(deviceId);
+        return ports == null ? null : ports.get(portNumber);
+    }
+
+    @Override
+    public boolean isAvailable(DeviceId deviceId) {
+        return availableDevices.contains(deviceId);
+    }
+
+    @Override
+    public DeviceEvent removeDevice(DeviceId deviceId) {
+        synchronized (this) {
+            Device device = devices.remove(deviceId);
+            return device == null ? null :
+                    new DeviceEvent(DEVICE_REMOVED, device, null);
+        }
+    }
+
+    private static boolean isAnnotationsEqual(Annotations lhs, Annotations rhs) {
+        if (lhs == rhs) {
+            return true;
+        }
+        if (lhs == null || rhs == null) {
+            return false;
+        }
+
+        if (!lhs.keys().equals(rhs.keys())) {
+            return false;
+        }
+
+        for (String key : lhs.keys()) {
+            if (!lhs.value(key).equals(rhs.value(key))) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Returns a Device, merging description given from multiple Providers.
+     *
+     * @param deviceId device identifier
+     * @param providerDescs Collection of Descriptions from multiple providers
+     * @return Device instance
+     */
+    private Device composeDevice(DeviceId deviceId,
+            ConcurrentMap<ProviderId, DeviceDescriptions> providerDescs) {
+
+        checkArgument(!providerDescs.isEmpty(), "No Device descriptions supplied");
+
+        ProviderId primary = pickPrimaryPID(providerDescs);
+
+        DeviceDescriptions desc = providerDescs.get(primary);
+
+        DeviceDescription base = desc.getDeviceDesc().value();
+        Type type = base.type();
+        String manufacturer = base.manufacturer();
+        String hwVersion = base.hwVersion();
+        String swVersion = base.swVersion();
+        String serialNumber = base.serialNumber();
+        DefaultAnnotations annotations = DefaultAnnotations.builder().build();
+        annotations = merge(annotations, base.annotations());
+
+        for (Entry<ProviderId, DeviceDescriptions> e : providerDescs.entrySet()) {
+            if (e.getKey().equals(primary)) {
+                continue;
+            }
+            // TODO: should keep track of Description timestamp
+            // and only merge conflicting keys when timestamp is newer
+            // Currently assuming there will never be a key conflict between
+            // providers
+
+            // annotation merging. not so efficient, should revisit later
+            annotations = merge(annotations, e.getValue().getDeviceDesc().value().annotations());
+        }
+
+        return new DefaultDevice(primary, deviceId , type, manufacturer,
+                            hwVersion, swVersion, serialNumber, annotations);
+    }
+
+    /**
+     * Returns a Port, merging description given from multiple Providers.
+     *
+     * @param device device the port is on
+     * @param number port number
+     * @param providerDescs Collection of Descriptions from multiple providers
+     * @return Port instance
+     */
+    private Port composePort(Device device, PortNumber number,
+                ConcurrentMap<ProviderId, DeviceDescriptions> providerDescs) {
+
+        ProviderId primary = pickPrimaryPID(providerDescs);
+        DeviceDescriptions primDescs = providerDescs.get(primary);
+        // if no primary, assume not enabled
+        // TODO: revisit this default port enabled/disabled behavior
+        boolean isEnabled = false;
+        DefaultAnnotations annotations = DefaultAnnotations.builder().build();
+
+        final Timestamped<PortDescription> portDesc = primDescs.getPortDesc(number);
+        if (portDesc != null) {
+            isEnabled = portDesc.value().isEnabled();
+            annotations = merge(annotations, portDesc.value().annotations());
+        }
+
+        for (Entry<ProviderId, DeviceDescriptions> e : providerDescs.entrySet()) {
+            if (e.getKey().equals(primary)) {
+                continue;
+            }
+            // TODO: should keep track of Description timestamp
+            // and only merge conflicting keys when timestamp is newer
+            // Currently assuming there will never be a key conflict between
+            // providers
+
+            // annotation merging. not so efficient, should revisit later
+            final Timestamped<PortDescription> otherPortDesc = e.getValue().getPortDesc(number);
+            if (otherPortDesc != null) {
+                annotations = merge(annotations, otherPortDesc.value().annotations());
+            }
+        }
+
+        return new DefaultPort(device, number, isEnabled, annotations);
+    }
+
+    /**
+     * @return primary ProviderID, or randomly chosen one if none exists
+     */
+    private ProviderId pickPrimaryPID(
+            ConcurrentMap<ProviderId, DeviceDescriptions> providerDescs) {
+        ProviderId fallBackPrimary = null;
+        for (Entry<ProviderId, DeviceDescriptions> e : providerDescs.entrySet()) {
+            if (!e.getKey().isAncillary()) {
+                return e.getKey();
+            } else if (fallBackPrimary == null) {
+                // pick randomly as a fallback in case there is no primary
+                fallBackPrimary = e.getKey();
+            }
+        }
+        return fallBackPrimary;
+    }
+
+    private static final class InitConcurrentHashMap<K, V> implements
+            ConcurrentInitializer<ConcurrentMap<K, V>> {
+        @Override
+        public ConcurrentMap<K, V> get() throws ConcurrentException {
+            return new ConcurrentHashMap<>();
+        }
+    }
+
+    public static final class InitDeviceDescs
+        implements ConcurrentInitializer<DeviceDescriptions> {
+
+        private final Timestamped<DeviceDescription> deviceDesc;
+
+        public InitDeviceDescs(Timestamped<DeviceDescription> deviceDesc) {
+            this.deviceDesc = checkNotNull(deviceDesc);
+        }
+        @Override
+        public DeviceDescriptions get() throws ConcurrentException {
+            return new DeviceDescriptions(deviceDesc);
+        }
+    }
+
+
+    /**
+     * Collection of Description of a Device and it's Ports given from a Provider.
+     */
+    public static class DeviceDescriptions {
+
+        private final AtomicReference<Timestamped<DeviceDescription>> deviceDesc;
+        private final ConcurrentMap<PortNumber, Timestamped<PortDescription>> portDescs;
+
+        public DeviceDescriptions(Timestamped<DeviceDescription> desc) {
+            this.deviceDesc = new AtomicReference<>(checkNotNull(desc));
+            this.portDescs = new ConcurrentHashMap<>();
+        }
+
+        public Timestamped<DeviceDescription> getDeviceDesc() {
+            return deviceDesc.get();
+        }
+
+        public Timestamped<PortDescription> getPortDesc(PortNumber number) {
+            return portDescs.get(number);
+        }
+
+        /**
+         * Puts DeviceDescription, merging annotations as necessary.
+         *
+         * @param newDesc new DeviceDescription
+         * @return previous DeviceDescription
+         */
+        public synchronized Timestamped<DeviceDescription> putDeviceDesc(Timestamped<DeviceDescription> newDesc) {
+            Timestamped<DeviceDescription> oldOne = deviceDesc.get();
+            Timestamped<DeviceDescription> newOne = newDesc;
+            if (oldOne != null) {
+                SparseAnnotations merged = merge(oldOne.value().annotations(),
+                                                 newDesc.value().annotations());
+                newOne = new Timestamped<DeviceDescription>(
+                        new DefaultDeviceDescription(newDesc.value(), merged),
+                        newDesc.timestamp());
+            }
+            return deviceDesc.getAndSet(newOne);
+        }
+
+        /**
+         * Puts PortDescription, merging annotations as necessary.
+         *
+         * @param newDesc new PortDescription
+         * @return previous PortDescription
+         */
+        public synchronized Timestamped<PortDescription> putPortDesc(Timestamped<PortDescription> newDesc) {
+            Timestamped<PortDescription> oldOne = portDescs.get(newDesc.value().portNumber());
+            Timestamped<PortDescription> newOne = newDesc;
+            if (oldOne != null) {
+                SparseAnnotations merged = merge(oldOne.value().annotations(),
+                                                 newDesc.value().annotations());
+                newOne = new Timestamped<PortDescription>(
+                        new DefaultPortDescription(newDesc.value(), merged),
+                        newDesc.timestamp());
+            }
+            return portDescs.put(newOne.value().portNumber(), newOne);
+        }
+    }
+}
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/OnosDistributedDeviceStore.java b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/OnosDistributedDeviceStore.java
deleted file mode 100644
index d912983..0000000
--- a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/OnosDistributedDeviceStore.java
+++ /dev/null
@@ -1,339 +0,0 @@
-package org.onlab.onos.store.device.impl;
-
-import static com.google.common.base.Predicates.notNull;
-import static com.google.common.base.Preconditions.checkState;
-
-import com.google.common.collect.FluentIterable;
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.ImmutableSet.Builder;
-
-import org.apache.felix.scr.annotations.Activate;
-import org.apache.felix.scr.annotations.Component;
-import org.apache.felix.scr.annotations.Deactivate;
-import org.apache.felix.scr.annotations.Reference;
-import org.apache.felix.scr.annotations.ReferenceCardinality;
-import org.apache.felix.scr.annotations.Service;
-import org.onlab.onos.net.DefaultDevice;
-import org.onlab.onos.net.DefaultPort;
-import org.onlab.onos.net.Device;
-import org.onlab.onos.net.DeviceId;
-import org.onlab.onos.net.Port;
-import org.onlab.onos.net.PortNumber;
-import org.onlab.onos.net.device.DeviceDescription;
-import org.onlab.onos.net.device.DeviceEvent;
-import org.onlab.onos.net.device.DeviceStore;
-import org.onlab.onos.net.device.DeviceStoreDelegate;
-import org.onlab.onos.net.device.PortDescription;
-import org.onlab.onos.net.provider.ProviderId;
-import org.onlab.onos.store.AbstractStore;
-import org.onlab.onos.store.ClockService;
-import org.onlab.onos.store.Timestamp;
-import org.slf4j.Logger;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-
-import static com.google.common.base.Preconditions.checkArgument;
-import static org.onlab.onos.net.device.DeviceEvent.Type.*;
-import static org.slf4j.LoggerFactory.getLogger;
-
-/**
- * Manages inventory of infrastructure devices using a protocol that takes into consideration
- * the order in which device events occur.
- */
-@Component(immediate = true)
-@Service
-public class OnosDistributedDeviceStore
-        extends AbstractStore<DeviceEvent, DeviceStoreDelegate>
-        implements DeviceStore {
-
-    private final Logger log = getLogger(getClass());
-
-    public static final String DEVICE_NOT_FOUND = "Device with ID %s not found";
-
-    private ConcurrentMap<DeviceId, VersionedValue<Device>> devices;
-    private ConcurrentMap<DeviceId, Map<PortNumber, VersionedValue<Port>>> devicePorts;
-
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected ClockService clockService;
-
-    @Activate
-    public void activate() {
-
-        devices = new ConcurrentHashMap<>();
-        devicePorts = new ConcurrentHashMap<>();
-
-        log.info("Started");
-    }
-
-    @Deactivate
-    public void deactivate() {
-        log.info("Stopped");
-    }
-
-    @Override
-    public int getDeviceCount() {
-        return devices.size();
-    }
-
-    @Override
-    public Iterable<Device> getDevices() {
-        Builder<Device> builder = ImmutableSet.builder();
-        synchronized (this) {
-            for (VersionedValue<Device> device : devices.values()) {
-                builder.add(device.entity());
-            }
-            return builder.build();
-        }
-    }
-
-    @Override
-    public Device getDevice(DeviceId deviceId) {
-        VersionedValue<Device> device = devices.get(deviceId);
-        checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
-        return device.entity();
-    }
-
-    @Override
-    public DeviceEvent createOrUpdateDevice(ProviderId providerId, DeviceId deviceId,
-                                            DeviceDescription deviceDescription) {
-        Timestamp newTimestamp = clockService.getTimestamp(deviceId);
-        VersionedValue<Device> device = devices.get(deviceId);
-
-        if (device == null) {
-            return createDevice(providerId, deviceId, deviceDescription, newTimestamp);
-        }
-
-        checkState(newTimestamp.compareTo(device.timestamp()) > 0,
-                "Existing device has a timestamp in the future!");
-
-        return updateDevice(providerId, device.entity(), deviceDescription, newTimestamp);
-    }
-
-    // Creates the device and returns the appropriate event if necessary.
-    private DeviceEvent createDevice(ProviderId providerId, DeviceId deviceId,
-                                     DeviceDescription desc, Timestamp timestamp) {
-        Device device = new DefaultDevice(providerId, deviceId, desc.type(),
-                                                 desc.manufacturer(),
-                                                 desc.hwVersion(), desc.swVersion(),
-                                                 desc.serialNumber());
-
-        devices.put(deviceId, new VersionedValue<>(device, true, timestamp));
-        // TODO,FIXME: broadcast a message telling peers of a device event.
-        return new DeviceEvent(DEVICE_ADDED, device, null);
-    }
-
-    // Updates the device and returns the appropriate event if necessary.
-    private DeviceEvent updateDevice(ProviderId providerId, Device device,
-                                     DeviceDescription desc, Timestamp timestamp) {
-        // We allow only certain attributes to trigger update
-        if (!Objects.equals(device.hwVersion(), desc.hwVersion()) ||
-                !Objects.equals(device.swVersion(), desc.swVersion())) {
-
-            Device updated = new DefaultDevice(providerId, device.id(),
-                                                      desc.type(),
-                                                      desc.manufacturer(),
-                                                      desc.hwVersion(),
-                                                      desc.swVersion(),
-                                                      desc.serialNumber());
-            devices.put(device.id(), new VersionedValue<Device>(updated, true, timestamp));
-            // FIXME: broadcast a message telling peers of a device event.
-            return new DeviceEvent(DeviceEvent.Type.DEVICE_UPDATED, updated, null);
-        }
-
-        // Otherwise merely attempt to change availability
-        Device updated = new DefaultDevice(providerId, device.id(),
-                desc.type(),
-                desc.manufacturer(),
-                desc.hwVersion(),
-                desc.swVersion(),
-                desc.serialNumber());
-
-        VersionedValue<Device> oldDevice = devices.put(device.id(),
-                new VersionedValue<Device>(updated, true, timestamp));
-        if (!oldDevice.isUp()) {
-            return new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device, null);
-        } else {
-            return null;
-        }
-    }
-
-    @Override
-    public DeviceEvent markOffline(DeviceId deviceId) {
-        VersionedValue<Device> device = devices.get(deviceId);
-        boolean willRemove = device != null && device.isUp();
-        if (!willRemove) {
-            return null;
-        }
-        Timestamp timestamp = clockService.getTimestamp(deviceId);
-        if (replaceIfLatest(device.entity(), false, timestamp)) {
-            return new DeviceEvent(DEVICE_AVAILABILITY_CHANGED, device.entity(), null);
-        }
-        return null;
-    }
-
-    // Replace existing value if its timestamp is older.
-    private synchronized boolean replaceIfLatest(Device device, boolean isUp, Timestamp timestamp) {
-        VersionedValue<Device> existingValue = devices.get(device.id());
-        if (timestamp.compareTo(existingValue.timestamp()) > 0) {
-            devices.put(device.id(), new VersionedValue<Device>(device, isUp, timestamp));
-            return true;
-        }
-        return false;
-    }
-
-    @Override
-    public List<DeviceEvent> updatePorts(ProviderId providerId, DeviceId deviceId,
-                                         List<PortDescription> portDescriptions) {
-        List<DeviceEvent> events = new ArrayList<>();
-        synchronized (this) {
-            VersionedValue<Device> device = devices.get(deviceId);
-            checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
-            Map<PortNumber, VersionedValue<Port>> ports = getPortMap(deviceId);
-            Timestamp newTimestamp = clockService.getTimestamp(deviceId);
-
-            // Add new ports
-            Set<PortNumber> processed = new HashSet<>();
-            for (PortDescription portDescription : portDescriptions) {
-                VersionedValue<Port> port = ports.get(portDescription.portNumber());
-                if (port == null) {
-                    events.add(createPort(device, portDescription, ports, newTimestamp));
-                }
-                checkState(newTimestamp.compareTo(port.timestamp()) > 0,
-                        "Existing port state has a timestamp in the future!");
-                events.add(updatePort(device.entity(), port.entity(), portDescription, ports, newTimestamp));
-                processed.add(portDescription.portNumber());
-            }
-
-            updatePortMap(deviceId, ports);
-
-            events.addAll(pruneOldPorts(device.entity(), ports, processed));
-        }
-        return FluentIterable.from(events).filter(notNull()).toList();
-    }
-
-    // Creates a new port based on the port description adds it to the map and
-    // Returns corresponding event.
-    //@GuardedBy("this")
-    private DeviceEvent createPort(VersionedValue<Device> device, PortDescription portDescription,
-                                   Map<PortNumber, VersionedValue<Port>> ports, Timestamp timestamp) {
-        Port port = new DefaultPort(device.entity(), portDescription.portNumber(),
-                                           portDescription.isEnabled());
-        ports.put(port.number(), new VersionedValue<Port>(port, true, timestamp));
-        updatePortMap(device.entity().id(), ports);
-        return new DeviceEvent(PORT_ADDED, device.entity(), port);
-    }
-
-    // Checks if the specified port requires update and if so, it replaces the
-    // existing entry in the map and returns corresponding event.
-    //@GuardedBy("this")
-    private DeviceEvent updatePort(Device device, Port port,
-                                   PortDescription portDescription,
-                                   Map<PortNumber, VersionedValue<Port>> ports,
-                                   Timestamp timestamp) {
-        if (port.isEnabled() != portDescription.isEnabled()) {
-            VersionedValue<Port> updatedPort = new VersionedValue<Port>(
-                    new DefaultPort(device, portDescription.portNumber(),
-                                    portDescription.isEnabled()),
-                    portDescription.isEnabled(),
-                    timestamp);
-            ports.put(port.number(), updatedPort);
-            updatePortMap(device.id(), ports);
-            return new DeviceEvent(PORT_UPDATED, device, updatedPort.entity());
-        }
-        return null;
-    }
-
-    // Prunes the specified list of ports based on which ports are in the
-    // processed list and returns list of corresponding events.
-    //@GuardedBy("this")
-    private List<DeviceEvent> pruneOldPorts(Device device,
-                                            Map<PortNumber, VersionedValue<Port>> ports,
-                                            Set<PortNumber> processed) {
-        List<DeviceEvent> events = new ArrayList<>();
-        Iterator<PortNumber> iterator = ports.keySet().iterator();
-        while (iterator.hasNext()) {
-            PortNumber portNumber = iterator.next();
-            if (!processed.contains(portNumber)) {
-                events.add(new DeviceEvent(PORT_REMOVED, device,
-                                           ports.get(portNumber).entity()));
-                iterator.remove();
-            }
-        }
-        if (!events.isEmpty()) {
-            updatePortMap(device.id(), ports);
-        }
-        return events;
-    }
-
-    // Gets the map of ports for the specified device; if one does not already
-    // exist, it creates and registers a new one.
-    // WARN: returned value is a copy, changes made to the Map
-    //       needs to be written back using updatePortMap
-    //@GuardedBy("this")
-    private Map<PortNumber, VersionedValue<Port>> getPortMap(DeviceId deviceId) {
-        Map<PortNumber, VersionedValue<Port>> ports = devicePorts.get(deviceId);
-        if (ports == null) {
-            ports = new HashMap<>();
-            // this probably is waste of time in most cases.
-            updatePortMap(deviceId, ports);
-        }
-        return ports;
-    }
-
-    //@GuardedBy("this")
-    private void updatePortMap(DeviceId deviceId, Map<PortNumber, VersionedValue<Port>> ports) {
-        devicePorts.put(deviceId, ports);
-    }
-
-    @Override
-    public DeviceEvent updatePortStatus(ProviderId providerId, DeviceId deviceId,
-                                        PortDescription portDescription) {
-        VersionedValue<Device> device = devices.get(deviceId);
-        checkArgument(device != null, DEVICE_NOT_FOUND, deviceId);
-        Map<PortNumber, VersionedValue<Port>> ports = getPortMap(deviceId);
-        VersionedValue<Port> port = ports.get(portDescription.portNumber());
-        Timestamp timestamp = clockService.getTimestamp(deviceId);
-        return updatePort(device.entity(), port.entity(), portDescription, ports, timestamp);
-    }
-
-    @Override
-    public List<Port> getPorts(DeviceId deviceId) {
-        Map<PortNumber, VersionedValue<Port>> versionedPorts = devicePorts.get(deviceId);
-        if (versionedPorts == null) {
-            return Collections.emptyList();
-        }
-        List<Port> ports = new ArrayList<>();
-        for (VersionedValue<Port> port : versionedPorts.values()) {
-            ports.add(port.entity());
-        }
-        return ports;
-    }
-
-    @Override
-    public Port getPort(DeviceId deviceId, PortNumber portNumber) {
-        Map<PortNumber, VersionedValue<Port>> ports = devicePorts.get(deviceId);
-        return ports == null ? null : ports.get(portNumber).entity();
-    }
-
-    @Override
-    public boolean isAvailable(DeviceId deviceId) {
-        return devices.get(deviceId).isUp();
-    }
-
-    @Override
-    public DeviceEvent removeDevice(DeviceId deviceId) {
-        VersionedValue<Device> previousDevice = devices.remove(deviceId);
-        return previousDevice == null ? null :
-            new DeviceEvent(DEVICE_REMOVED, previousDevice.entity(), null);
-    }
-}
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/package-info.java b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/package-info.java
index aa644db..c1f5aad 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/package-info.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/package-info.java
@@ -1,4 +1,4 @@
 /**
  * Implementation of device store using distributed distributed p2p synchronization protocol.
  */
-package org.onlab.onos.store.device.impl;
\ No newline at end of file
+package org.onlab.onos.store.device.impl;
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/link/impl/OnosDistributedLinkStore.java b/core/store/dist/src/main/java/org/onlab/onos/store/link/impl/OnosDistributedLinkStore.java
index 5df25b4..a59b151 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/link/impl/OnosDistributedLinkStore.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/link/impl/OnosDistributedLinkStore.java
@@ -42,6 +42,7 @@
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkState;
 
+//TODO: Add support for multiple provider and annotations
 /**
  * Manages inventory of infrastructure links using a protocol that takes into consideration
  * the order in which events occur.
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/link/impl/package-info.java b/core/store/dist/src/main/java/org/onlab/onos/store/link/impl/package-info.java
index 127dc84..c675f84 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/link/impl/package-info.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/link/impl/package-info.java
@@ -1,4 +1,4 @@
 /**
  * Implementation of link store using distributed p2p synchronization protocol.
  */
-package org.onlab.onos.store.link.impl;
\ No newline at end of file
+package org.onlab.onos.store.link.impl;
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/serializers/MastershipBasedTimestampSerializer.java b/core/store/dist/src/main/java/org/onlab/onos/store/serializers/MastershipBasedTimestampSerializer.java
new file mode 100644
index 0000000..9250076
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/serializers/MastershipBasedTimestampSerializer.java
@@ -0,0 +1,36 @@
+package org.onlab.onos.store.serializers;
+
+import org.onlab.onos.store.common.impl.MastershipBasedTimestamp;
+
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+
+// To be used if Timestamp ever needs to cross bundle boundary.
+/**
+ * Kryo Serializer for {@link MastershipBasedTimestamp}.
+ */
+public class MastershipBasedTimestampSerializer extends Serializer<MastershipBasedTimestamp> {
+
+    /**
+     * Default constructor.
+     */
+    public MastershipBasedTimestampSerializer() {
+        // non-null, immutable
+        super(false, true);
+    }
+
+    @Override
+    public void write(Kryo kryo, Output output, MastershipBasedTimestamp object) {
+        output.writeInt(object.termNumber());
+        output.writeInt(object.sequenceNumber());
+    }
+
+    @Override
+    public MastershipBasedTimestamp read(Kryo kryo, Input input, Class<MastershipBasedTimestamp> type) {
+        final int term = input.readInt();
+        final int sequence = input.readInt();
+        return new MastershipBasedTimestamp(term, sequence);
+    }
+}
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/serializers/OnosTimestampSerializer.java b/core/store/dist/src/main/java/org/onlab/onos/store/serializers/OnosTimestampSerializer.java
deleted file mode 100644
index 192e035..0000000
--- a/core/store/dist/src/main/java/org/onlab/onos/store/serializers/OnosTimestampSerializer.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package org.onlab.onos.store.serializers;
-
-import org.onlab.onos.store.impl.OnosTimestamp;
-
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
-
-/**
- * Kryo Serializer for {@link OnosTimestamp}.
- */
-public class OnosTimestampSerializer extends Serializer<OnosTimestamp> {
-
-    /**
-     * Default constructor.
-     */
-    public OnosTimestampSerializer() {
-        // non-null, immutable
-        super(false, true);
-    }
-
-    @Override
-    public void write(Kryo kryo, Output output, OnosTimestamp object) {
-        output.writeInt(object.termNumber());
-        output.writeInt(object.sequenceNumber());
-    }
-
-    @Override
-    public OnosTimestamp read(Kryo kryo, Input input, Class<OnosTimestamp> type) {
-        final int term = input.readInt();
-        final int sequence = input.readInt();
-        return new OnosTimestamp(term, sequence);
-    }
-}
diff --git a/core/store/dist/src/test/java/org/onlab/onos/store/common/impl/MastershipBasedTimestampTest.java b/core/store/dist/src/test/java/org/onlab/onos/store/common/impl/MastershipBasedTimestampTest.java
new file mode 100644
index 0000000..ea63ef8
--- /dev/null
+++ b/core/store/dist/src/test/java/org/onlab/onos/store/common/impl/MastershipBasedTimestampTest.java
@@ -0,0 +1,95 @@
+package org.onlab.onos.store.common.impl;
+
+import static org.junit.Assert.*;
+
+import java.nio.ByteBuffer;
+
+import org.junit.Test;
+import org.onlab.onos.store.Timestamp;
+import org.onlab.onos.store.serializers.MastershipBasedTimestampSerializer;
+import org.onlab.util.KryoPool;
+
+import com.google.common.testing.EqualsTester;
+
+/**
+ * Test of {@link MastershipBasedTimestamp}.
+ */
+public class MastershipBasedTimestampTest {
+
+    private static final Timestamp TS_1_1 = new MastershipBasedTimestamp(1, 1);
+    private static final Timestamp TS_1_2 = new MastershipBasedTimestamp(1, 2);
+    private static final Timestamp TS_2_1 = new MastershipBasedTimestamp(2, 1);
+    private static final Timestamp TS_2_2 = new MastershipBasedTimestamp(2, 2);
+
+    @Test
+    public final void testBasic() {
+        final int termNumber = 5;
+        final int sequenceNumber = 6;
+        MastershipBasedTimestamp ts = new MastershipBasedTimestamp(termNumber,
+                                                sequenceNumber);
+
+        assertEquals(termNumber, ts.termNumber());
+        assertEquals(sequenceNumber, ts.sequenceNumber());
+    }
+
+    @Test
+    public final void testCompareTo() {
+        assertTrue(TS_1_1.compareTo(TS_1_1) == 0);
+        assertTrue(TS_1_1.compareTo(new MastershipBasedTimestamp(1, 1)) == 0);
+
+        assertTrue(TS_1_1.compareTo(TS_1_2) < 0);
+        assertTrue(TS_1_2.compareTo(TS_1_1) > 0);
+
+        assertTrue(TS_1_2.compareTo(TS_2_1) < 0);
+        assertTrue(TS_1_2.compareTo(TS_2_2) < 0);
+        assertTrue(TS_2_1.compareTo(TS_1_1) > 0);
+        assertTrue(TS_2_2.compareTo(TS_1_1) > 0);
+    }
+
+    @Test
+    public final void testEqualsObject() {
+        new EqualsTester()
+        .addEqualityGroup(new MastershipBasedTimestamp(1, 1),
+                          new MastershipBasedTimestamp(1, 1), TS_1_1)
+        .addEqualityGroup(new MastershipBasedTimestamp(1, 2),
+                          new MastershipBasedTimestamp(1, 2), TS_1_2)
+        .addEqualityGroup(new MastershipBasedTimestamp(2, 1),
+                          new MastershipBasedTimestamp(2, 1), TS_2_1)
+        .addEqualityGroup(new MastershipBasedTimestamp(2, 2),
+                          new MastershipBasedTimestamp(2, 2), TS_2_2)
+        .testEquals();
+    }
+
+    @Test
+    public final void testKryoSerializable() {
+        final ByteBuffer buffer = ByteBuffer.allocate(1 * 1024 * 1024);
+        final KryoPool kryos = KryoPool.newBuilder()
+                .register(MastershipBasedTimestamp.class)
+                .build();
+
+        kryos.serialize(TS_2_1, buffer);
+        buffer.flip();
+        Timestamp copy = kryos.deserialize(buffer);
+
+        new EqualsTester()
+            .addEqualityGroup(TS_2_1, copy)
+            .testEquals();
+    }
+
+    @Test
+    public final void testKryoSerializableWithHandcraftedSerializer() {
+        final ByteBuffer buffer = ByteBuffer.allocate(1 * 1024 * 1024);
+        final KryoPool kryos = KryoPool.newBuilder()
+                .register(MastershipBasedTimestamp.class, new MastershipBasedTimestampSerializer())
+                .build();
+
+        kryos.serialize(TS_1_2, buffer);
+        buffer.flip();
+        Timestamp copy = kryos.deserialize(buffer);
+
+        new EqualsTester()
+            .addEqualityGroup(TS_1_2, copy)
+            .testEquals();
+    }
+
+}
diff --git a/core/store/dist/src/test/java/org/onlab/onos/store/common/impl/TimestampedTest.java b/core/store/dist/src/test/java/org/onlab/onos/store/common/impl/TimestampedTest.java
new file mode 100644
index 0000000..4b44d40
--- /dev/null
+++ b/core/store/dist/src/test/java/org/onlab/onos/store/common/impl/TimestampedTest.java
@@ -0,0 +1,94 @@
+package org.onlab.onos.store.common.impl;
+
+import static org.junit.Assert.*;
+
+import java.nio.ByteBuffer;
+
+import org.junit.Test;
+import org.onlab.onos.store.Timestamp;
+import org.onlab.util.KryoPool;
+
+import com.google.common.testing.EqualsTester;
+
+/**
+ * Test of {@link Timestamped}.
+ */
+public class TimestampedTest {
+
+    private static final Timestamp TS_1_1 = new MastershipBasedTimestamp(1, 1);
+    private static final Timestamp TS_1_2 = new MastershipBasedTimestamp(1, 2);
+    private static final Timestamp TS_2_1 = new MastershipBasedTimestamp(2, 1);
+
+    @Test
+    public final void testHashCode() {
+        Timestamped<String> a = new Timestamped<>("a", TS_1_1);
+        Timestamped<String> b = new Timestamped<>("b", TS_1_1);
+        assertTrue("value does not impact hashCode",
+                a.hashCode() == b.hashCode());
+    }
+
+    @Test
+    public final void testEquals() {
+        Timestamped<String> a = new Timestamped<>("a", TS_1_1);
+        Timestamped<String> b = new Timestamped<>("b", TS_1_1);
+        assertTrue("value does not impact equality",
+                a.equals(b));
+
+        new EqualsTester()
+        .addEqualityGroup(new Timestamped<>("a", TS_1_1),
+                          new Timestamped<>("b", TS_1_1),
+                          new Timestamped<>("c", TS_1_1))
+        .addEqualityGroup(new Timestamped<>("a", TS_1_2),
+                          new Timestamped<>("b", TS_1_2),
+                          new Timestamped<>("c", TS_1_2))
+        .addEqualityGroup(new Timestamped<>("a", TS_2_1),
+                          new Timestamped<>("b", TS_2_1),
+                          new Timestamped<>("c", TS_2_1))
+        .testEquals();
+
+    }
+
+    @Test
+    public final void testValue() {
+       final Integer n = Integer.valueOf(42);
+       Timestamped<Integer> tsv = new Timestamped<>(n, TS_1_1);
+       assertSame(n, tsv.value());
+
+    }
+
+    @Test(expected = NullPointerException.class)
+    public final void testValueNonNull() {
+        new Timestamped<>(null, TS_1_1);
+    }
+
+    @Test(expected = NullPointerException.class)
+    public final void testTimestampNonNull() {
+        new Timestamped<>("Foo", null);
+    }
+
+    @Test
+    public final void testIsNewer() {
+        Timestamped<String> a = new Timestamped<>("a", TS_1_2);
+        Timestamped<String> b = new Timestamped<>("b", TS_1_1);
+        assertTrue(a.isNewer(b));
+        assertFalse(b.isNewer(a));
+    }
+
+    @Test
+    public final void testKryoSerializable() {
+        final ByteBuffer buffer = ByteBuffer.allocate(1 * 1024 * 1024);
+        final KryoPool kryos = KryoPool.newBuilder()
+                .register(Timestamped.class,
+                        MastershipBasedTimestamp.class)
+                .build();
+
+        Timestamped<String> original = new Timestamped<>("foobar", TS_1_1);
+        kryos.serialize(original, buffer);
+        buffer.flip();
+        Timestamped<String> copy = kryos.deserialize(buffer);
+
+        new EqualsTester()
+            .addEqualityGroup(original, copy)
+            .testEquals();
+    }
+}
diff --git a/core/store/dist/src/test/java/org/onlab/onos/store/device/impl/GossipDeviceStoreTest.java b/core/store/dist/src/test/java/org/onlab/onos/store/device/impl/GossipDeviceStoreTest.java
new file mode 100644
index 0000000..09c3098
--- /dev/null
+++ b/core/store/dist/src/test/java/org/onlab/onos/store/device/impl/GossipDeviceStoreTest.java
@@ -0,0 +1,525 @@
+package org.onlab.onos.store.device.impl;
+
+import static org.junit.Assert.*;
+import static org.onlab.onos.net.Device.Type.SWITCH;
+import static org.onlab.onos.net.DeviceId.deviceId;
+import static org.onlab.onos.net.device.DeviceEvent.Type.*;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.net.Annotations;
+import org.onlab.onos.net.DefaultAnnotations;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.SparseAnnotations;
+import org.onlab.onos.net.device.DefaultDeviceDescription;
+import org.onlab.onos.net.device.DefaultPortDescription;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.device.DeviceEvent;
+import org.onlab.onos.net.device.DeviceStore;
+import org.onlab.onos.net.device.DeviceStoreDelegate;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.ClockService;
+
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Sets;
+
+
+// TODO add tests for remote replication
+/**
+ * Test of the gossip based distributed DeviceStore implementation.
+ */
+public class GossipDeviceStoreTest {
+
+    private static final ProviderId PID = new ProviderId("of", "foo");
+    private static final ProviderId PIDA = new ProviderId("of", "bar", true);
+    private static final DeviceId DID1 = deviceId("of:foo");
+    private static final DeviceId DID2 = deviceId("of:bar");
+    private static final String MFR = "whitebox";
+    private static final String HW = "1.1.x";
+    private static final String SW1 = "3.8.1";
+    private static final String SW2 = "3.9.5";
+    private static final String SN = "43311-12345";
+
+    private static final PortNumber P1 = PortNumber.portNumber(1);
+    private static final PortNumber P2 = PortNumber.portNumber(2);
+    private static final PortNumber P3 = PortNumber.portNumber(3);
+
+    private static final SparseAnnotations A1 = DefaultAnnotations.builder()
+            .set("A1", "a1")
+            .set("B1", "b1")
+            .build();
+    private static final SparseAnnotations A1_2 = DefaultAnnotations.builder()
+            .remove("A1")
+            .set("B3", "b3")
+            .build();
+    private static final SparseAnnotations A2 = DefaultAnnotations.builder()
+            .set("A2", "a2")
+            .set("B2", "b2")
+            .build();
+    private static final SparseAnnotations A2_2 = DefaultAnnotations.builder()
+            .remove("A2")
+            .set("B4", "b4")
+            .build();
+
+    private static final NodeId MYSELF = new NodeId("myself");
+
+    private GossipDeviceStore gossipDeviceStore;
+    private DeviceStore deviceStore;
+
+    private DeviceClockManager deviceClockManager;
+    private ClockService clockService;
+
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+    }
+
+    @AfterClass
+    public static void tearDownAfterClass() throws Exception {
+    }
+
+
+    @Before
+    public void setUp() throws Exception {
+        deviceClockManager = new DeviceClockManager();
+        deviceClockManager.activate();
+        clockService = deviceClockManager;
+
+        deviceClockManager.setMastershipTerm(DID1, MastershipTerm.of(MYSELF, 1));
+        deviceClockManager.setMastershipTerm(DID2, MastershipTerm.of(MYSELF, 2));
+
+        gossipDeviceStore = new TestGossipDeviceStore(clockService);
+        gossipDeviceStore.activate();
+        deviceStore = gossipDeviceStore;
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        gossipDeviceStore.deactivate();
+        deviceClockManager.deactivate();
+    }
+
+    private void putDevice(DeviceId deviceId, String swVersion) {
+        DeviceDescription description =
+                new DefaultDeviceDescription(deviceId.uri(), SWITCH, MFR,
+                        HW, swVersion, SN);
+        deviceStore.createOrUpdateDevice(PID, deviceId, description);
+    }
+
+    private void putDeviceAncillary(DeviceId deviceId, String swVersion) {
+        DeviceDescription description =
+                new DefaultDeviceDescription(deviceId.uri(), SWITCH, MFR,
+                        HW, swVersion, SN);
+        deviceStore.createOrUpdateDevice(PIDA, deviceId, description);
+    }
+
+    private static void assertDevice(DeviceId id, String swVersion, Device device) {
+        assertNotNull(device);
+        assertEquals(id, device.id());
+        assertEquals(MFR, device.manufacturer());
+        assertEquals(HW, device.hwVersion());
+        assertEquals(swVersion, device.swVersion());
+        assertEquals(SN, device.serialNumber());
+    }
+
+    /**
+     * Verifies that Annotations created by merging {@code annotations} is
+     * equal to actual Annotations.
+     *
+     * @param actual Annotations to check
+     * @param annotations
+     */
+    private static void assertAnnotationsEquals(Annotations actual, SparseAnnotations... annotations) {
+        DefaultAnnotations expected = DefaultAnnotations.builder().build();
+        for (SparseAnnotations a : annotations) {
+            expected = DefaultAnnotations.merge(expected, a);
+        }
+        assertEquals(expected.keys(), actual.keys());
+        for (String key : expected.keys()) {
+            assertEquals(expected.value(key), actual.value(key));
+        }
+    }
+
+    @Test
+    public final void testGetDeviceCount() {
+        assertEquals("initialy empty", 0, deviceStore.getDeviceCount());
+
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW2);
+        putDevice(DID1, SW1);
+
+        assertEquals("expect 2 uniq devices", 2, deviceStore.getDeviceCount());
+    }
+
+    @Test
+    public final void testGetDevices() {
+        assertEquals("initialy empty", 0, Iterables.size(deviceStore.getDevices()));
+
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW2);
+        putDevice(DID1, SW1);
+
+        assertEquals("expect 2 uniq devices",
+                2, Iterables.size(deviceStore.getDevices()));
+
+        Map<DeviceId, Device> devices = new HashMap<>();
+        for (Device device : deviceStore.getDevices()) {
+            devices.put(device.id(), device);
+        }
+
+        assertDevice(DID1, SW1, devices.get(DID1));
+        assertDevice(DID2, SW2, devices.get(DID2));
+
+        // add case for new node?
+    }
+
+    @Test
+    public final void testGetDevice() {
+
+        putDevice(DID1, SW1);
+
+        assertDevice(DID1, SW1, deviceStore.getDevice(DID1));
+        assertNull("DID2 shouldn't be there", deviceStore.getDevice(DID2));
+    }
+
+    @Test
+    public final void testCreateOrUpdateDevice() {
+        DeviceDescription description =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW1, SN);
+        DeviceEvent event = deviceStore.createOrUpdateDevice(PID, DID1, description);
+        assertEquals(DEVICE_ADDED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+
+        DeviceDescription description2 =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW2, SN);
+        DeviceEvent event2 = deviceStore.createOrUpdateDevice(PID, DID1, description2);
+        assertEquals(DEVICE_UPDATED, event2.type());
+        assertDevice(DID1, SW2, event2.subject());
+
+        assertNull("No change expected", deviceStore.createOrUpdateDevice(PID, DID1, description2));
+    }
+
+    @Test
+    public final void testCreateOrUpdateDeviceAncillary() {
+        DeviceDescription description =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW1, SN, A2);
+        DeviceEvent event = deviceStore.createOrUpdateDevice(PIDA, DID1, description);
+        assertEquals(DEVICE_ADDED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+        assertEquals(PIDA, event.subject().providerId());
+        assertAnnotationsEquals(event.subject().annotations(), A2);
+        assertFalse("Ancillary will not bring device up", deviceStore.isAvailable(DID1));
+
+        DeviceDescription description2 =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW2, SN, A1);
+        DeviceEvent event2 = deviceStore.createOrUpdateDevice(PID, DID1, description2);
+        assertEquals(DEVICE_UPDATED, event2.type());
+        assertDevice(DID1, SW2, event2.subject());
+        assertEquals(PID, event2.subject().providerId());
+        assertAnnotationsEquals(event2.subject().annotations(), A1, A2);
+        assertTrue(deviceStore.isAvailable(DID1));
+
+        assertNull("No change expected", deviceStore.createOrUpdateDevice(PID, DID1, description2));
+
+        // For now, Ancillary is ignored once primary appears
+        assertNull("No change expected", deviceStore.createOrUpdateDevice(PIDA, DID1, description));
+
+        // But, Ancillary annotations will be in effect
+        DeviceDescription description3 =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW1, SN, A2_2);
+        DeviceEvent event3 = deviceStore.createOrUpdateDevice(PIDA, DID1, description3);
+        assertEquals(DEVICE_UPDATED, event3.type());
+        // basic information will be the one from Primary
+        assertDevice(DID1, SW2, event3.subject());
+        assertEquals(PID, event3.subject().providerId());
+        // but annotation from Ancillary will be merged
+        assertAnnotationsEquals(event3.subject().annotations(), A1, A2, A2_2);
+        assertTrue(deviceStore.isAvailable(DID1));
+    }
+
+
+    @Test
+    public final void testMarkOffline() {
+
+        putDevice(DID1, SW1);
+        assertTrue(deviceStore.isAvailable(DID1));
+
+        DeviceEvent event = deviceStore.markOffline(DID1);
+        assertEquals(DEVICE_AVAILABILITY_CHANGED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+        assertFalse(deviceStore.isAvailable(DID1));
+
+        DeviceEvent event2 = deviceStore.markOffline(DID1);
+        assertNull("No change, no event", event2);
+}
+
+    @Test
+    public final void testUpdatePorts() {
+        putDevice(DID1, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, true)
+                );
+
+        List<DeviceEvent> events = deviceStore.updatePorts(PID, DID1, pds);
+
+        Set<PortNumber> expectedPorts = Sets.newHashSet(P1, P2);
+        for (DeviceEvent event : events) {
+            assertEquals(PORT_ADDED, event.type());
+            assertDevice(DID1, SW1, event.subject());
+            assertTrue("PortNumber is one of expected",
+                    expectedPorts.remove(event.port().number()));
+            assertTrue("Port is enabled", event.port().isEnabled());
+        }
+        assertTrue("Event for all expectedport appeared", expectedPorts.isEmpty());
+
+
+        List<PortDescription> pds2 = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, false),
+                new DefaultPortDescription(P2, true),
+                new DefaultPortDescription(P3, true)
+                );
+
+        events = deviceStore.updatePorts(PID, DID1, pds2);
+        assertFalse("event should be triggered", events.isEmpty());
+        for (DeviceEvent event : events) {
+            PortNumber num = event.port().number();
+            if (P1.equals(num)) {
+                assertEquals(PORT_UPDATED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertFalse("Port is disabled", event.port().isEnabled());
+            } else if (P2.equals(num)) {
+                fail("P2 event not expected.");
+            } else if (P3.equals(num)) {
+                assertEquals(PORT_ADDED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertTrue("Port is enabled", event.port().isEnabled());
+            } else {
+                fail("Unknown port number encountered: " + num);
+            }
+        }
+
+        List<PortDescription> pds3 = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, false),
+                new DefaultPortDescription(P2, true)
+                );
+        events = deviceStore.updatePorts(PID, DID1, pds3);
+        assertFalse("event should be triggered", events.isEmpty());
+        for (DeviceEvent event : events) {
+            PortNumber num = event.port().number();
+            if (P1.equals(num)) {
+                fail("P1 event not expected.");
+            } else if (P2.equals(num)) {
+                fail("P2 event not expected.");
+            } else if (P3.equals(num)) {
+                assertEquals(PORT_REMOVED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                assertTrue("Port was enabled", event.port().isEnabled());
+            } else {
+                fail("Unknown port number encountered: " + num);
+            }
+        }
+
+    }
+
+    @Test
+    public final void testUpdatePortStatus() {
+        putDevice(DID1, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true)
+                );
+        deviceStore.updatePorts(PID, DID1, pds);
+
+        DeviceEvent event = deviceStore.updatePortStatus(PID, DID1,
+                new DefaultPortDescription(P1, false));
+        assertEquals(PORT_UPDATED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+        assertEquals(P1, event.port().number());
+        assertFalse("Port is disabled", event.port().isEnabled());
+
+    }
+    @Test
+    public final void testUpdatePortStatusAncillary() {
+        putDeviceAncillary(DID1, SW1);
+        putDevice(DID1, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true, A1)
+                );
+        deviceStore.updatePorts(PID, DID1, pds);
+
+        DeviceEvent event = deviceStore.updatePortStatus(PID, DID1,
+                new DefaultPortDescription(P1, false, A1_2));
+        assertEquals(PORT_UPDATED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+        assertEquals(P1, event.port().number());
+        assertAnnotationsEquals(event.port().annotations(), A1, A1_2);
+        assertFalse("Port is disabled", event.port().isEnabled());
+
+        DeviceEvent event2 = deviceStore.updatePortStatus(PIDA, DID1,
+                new DefaultPortDescription(P1, true));
+        assertNull("Ancillary is ignored if primary exists", event2);
+
+        // but, Ancillary annotation update will be notified
+        DeviceEvent event3 = deviceStore.updatePortStatus(PIDA, DID1,
+                new DefaultPortDescription(P1, true, A2));
+        assertEquals(PORT_UPDATED, event3.type());
+        assertDevice(DID1, SW1, event3.subject());
+        assertEquals(P1, event3.port().number());
+        assertAnnotationsEquals(event3.port().annotations(), A1, A1_2, A2);
+        assertFalse("Port is disabled", event3.port().isEnabled());
+
+        // port only reported from Ancillary will be notified as down
+        DeviceEvent event4 = deviceStore.updatePortStatus(PIDA, DID1,
+                new DefaultPortDescription(P2, true));
+        assertEquals(PORT_ADDED, event4.type());
+        assertDevice(DID1, SW1, event4.subject());
+        assertEquals(P2, event4.port().number());
+        assertAnnotationsEquals(event4.port().annotations());
+        assertFalse("Port is disabled if not given from primary provider",
+                        event4.port().isEnabled());
+    }
+
+    @Test
+    public final void testGetPorts() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, true)
+                );
+        deviceStore.updatePorts(PID, DID1, pds);
+
+        Set<PortNumber> expectedPorts = Sets.newHashSet(P1, P2);
+        List<Port> ports = deviceStore.getPorts(DID1);
+        for (Port port : ports) {
+            assertTrue("Port is enabled", port.isEnabled());
+            assertTrue("PortNumber is one of expected",
+                    expectedPorts.remove(port.number()));
+        }
+        assertTrue("Event for all expectedport appeared", expectedPorts.isEmpty());
+
+
+        assertTrue("DID2 has no ports", deviceStore.getPorts(DID2).isEmpty());
+    }
+
+    @Test
+    public final void testGetPort() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+        List<PortDescription> pds = Arrays.<PortDescription>asList(
+                new DefaultPortDescription(P1, true),
+                new DefaultPortDescription(P2, false)
+                );
+        deviceStore.updatePorts(PID, DID1, pds);
+
+        Port port1 = deviceStore.getPort(DID1, P1);
+        assertEquals(P1, port1.number());
+        assertTrue("Port is enabled", port1.isEnabled());
+
+        Port port2 = deviceStore.getPort(DID1, P2);
+        assertEquals(P2, port2.number());
+        assertFalse("Port is disabled", port2.isEnabled());
+
+        Port port3 = deviceStore.getPort(DID1, P3);
+        assertNull("P3 not expected", port3);
+    }
+
+    @Test
+    public final void testRemoveDevice() {
+        putDevice(DID1, SW1);
+        putDevice(DID2, SW1);
+
+        assertEquals(2, deviceStore.getDeviceCount());
+
+        DeviceEvent event = deviceStore.removeDevice(DID1);
+        assertEquals(DEVICE_REMOVED, event.type());
+        assertDevice(DID1, SW1, event.subject());
+
+        assertEquals(1, deviceStore.getDeviceCount());
+    }
+
+    // If Delegates should be called only on remote events,
+    // then Simple* should never call them, thus not test required.
+    // TODO add test for Port events when we have them
+    @Ignore("Ignore until Delegate spec. is clear.")
+    @Test
+    public final void testEvents() throws InterruptedException {
+        final CountDownLatch addLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkAdd = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_ADDED, event.type());
+                assertDevice(DID1, SW1, event.subject());
+                addLatch.countDown();
+            }
+        };
+        final CountDownLatch updateLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkUpdate = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_UPDATED, event.type());
+                assertDevice(DID1, SW2, event.subject());
+                updateLatch.countDown();
+            }
+        };
+        final CountDownLatch removeLatch = new CountDownLatch(1);
+        DeviceStoreDelegate checkRemove = new DeviceStoreDelegate() {
+            @Override
+            public void notify(DeviceEvent event) {
+                assertEquals(DEVICE_REMOVED, event.type());
+                assertDevice(DID1, SW2, event.subject());
+                removeLatch.countDown();
+            }
+        };
+
+        DeviceDescription description =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW1, SN);
+        deviceStore.setDelegate(checkAdd);
+        deviceStore.createOrUpdateDevice(PID, DID1, description);
+        assertTrue("Add event fired", addLatch.await(1, TimeUnit.SECONDS));
+
+
+        DeviceDescription description2 =
+                new DefaultDeviceDescription(DID1.uri(), SWITCH, MFR,
+                        HW, SW2, SN);
+        deviceStore.unsetDelegate(checkAdd);
+        deviceStore.setDelegate(checkUpdate);
+        deviceStore.createOrUpdateDevice(PID, DID1, description2);
+        assertTrue("Update event fired", updateLatch.await(1, TimeUnit.SECONDS));
+
+        deviceStore.unsetDelegate(checkUpdate);
+        deviceStore.setDelegate(checkRemove);
+        deviceStore.removeDevice(DID1);
+        assertTrue("Remove event fired", removeLatch.await(1, TimeUnit.SECONDS));
+    }
+
+    private static final class TestGossipDeviceStore extends GossipDeviceStore {
+
+        public TestGossipDeviceStore(ClockService clockService) {
+            this.clockService = clockService;
+        }
+    }
+}
diff --git a/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java b/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java
index 5feb1ba..2ecd525 100644
--- a/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java
+++ b/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/DistributedDeviceStore.java
@@ -47,6 +47,7 @@
 import static org.onlab.onos.net.device.DeviceEvent.Type.*;
 import static org.slf4j.LoggerFactory.getLogger;
 
+//TODO: Add support for multiple provider and annotations
 /**
  * Manages inventory of infrastructure devices using Hazelcast-backed map.
  */
diff --git a/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/NoOpClockProviderService.java b/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/NoOpClockProviderService.java
new file mode 100644
index 0000000..b68620a
--- /dev/null
+++ b/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/NoOpClockProviderService.java
@@ -0,0 +1,20 @@
+package org.onlab.onos.store.device.impl;
+
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.ClockProviderService;
+
+// FIXME: Code clone in onos-core-trivial, onos-core-hz-net
+/**
+ * Dummy implementation of {@link ClockProviderService}.
+ */
+@Component(immediate = true)
+@Service
+public class NoOpClockProviderService implements ClockProviderService {
+
+    @Override
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {
+    }
+}
diff --git a/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/NoOpClockService.java b/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/NoOpClockService.java
deleted file mode 100644
index 2c443e9..0000000
--- a/core/store/hz/net/src/main/java/org/onlab/onos/store/device/impl/NoOpClockService.java
+++ /dev/null
@@ -1,32 +0,0 @@
-package org.onlab.onos.store.device.impl;
-
-import org.apache.felix.scr.annotations.Component;
-import org.apache.felix.scr.annotations.Service;
-import org.onlab.onos.cluster.MastershipTerm;
-import org.onlab.onos.net.DeviceId;
-import org.onlab.onos.store.ClockService;
-import org.onlab.onos.store.Timestamp;
-
-// FIXME: Code clone in onos-core-trivial, onos-core-hz-net
-/**
- * Dummy implementation of {@link ClockService}.
- */
-@Component(immediate = true)
-@Service
-public class NoOpClockService implements ClockService {
-
-    @Override
-    public Timestamp getTimestamp(DeviceId deviceId) {
-        return new Timestamp() {
-
-            @Override
-            public int compareTo(Timestamp o) {
-                throw new IllegalStateException("Never expected to be used.");
-            }
-        };
-    }
-
-    @Override
-    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {
-    }
-}
diff --git a/core/store/hz/net/src/main/java/org/onlab/onos/store/link/impl/DistributedLinkStore.java b/core/store/hz/net/src/main/java/org/onlab/onos/store/link/impl/DistributedLinkStore.java
index 5161f2f..5f5184f 100644
--- a/core/store/hz/net/src/main/java/org/onlab/onos/store/link/impl/DistributedLinkStore.java
+++ b/core/store/hz/net/src/main/java/org/onlab/onos/store/link/impl/DistributedLinkStore.java
@@ -38,6 +38,7 @@
 import com.google.common.collect.ImmutableSet.Builder;
 import com.hazelcast.core.IMap;
 
+//TODO: Add support for multiple provider and annotations
 /**
  * Manages inventory of infrastructure links using Hazelcast-backed map.
  */
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ConnectPointSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ConnectPointSerializer.java
index 46badcb..14a64d2 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ConnectPointSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ConnectPointSerializer.java
@@ -3,7 +3,6 @@
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.ElementId;
 import org.onlab.onos.net.PortNumber;
-
 import com.esotericsoftware.kryo.Kryo;
 import com.esotericsoftware.kryo.Serializer;
 import com.esotericsoftware.kryo.io.Input;
@@ -15,7 +14,7 @@
 public class ConnectPointSerializer extends Serializer<ConnectPoint> {
 
     /**
-     * Default constructor.
+     * Creates {@link ConnectPointSerializer} serializer instance.
      */
     public ConnectPointSerializer() {
         // non-null, immutable
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultLinkSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultLinkSerializer.java
index 5ee273d..06d01b5 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultLinkSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultLinkSerializer.java
@@ -16,7 +16,7 @@
 public class DefaultLinkSerializer extends Serializer<DefaultLink> {
 
     /**
-     * Default constructor.
+     * Creates {@link DefaultLink} serializer instance.
      */
     public DefaultLinkSerializer() {
         // non-null, immutable
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultPortSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultPortSerializer.java
index 8455e80..5dc310b 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultPortSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DefaultPortSerializer.java
@@ -16,7 +16,7 @@
         Serializer<DefaultPort> {
 
     /**
-     * Default constructor.
+     * Creates {@link DefaultPort} serializer instance.
      */
     public DefaultPortSerializer() {
         // non-null, immutable
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DeviceIdSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DeviceIdSerializer.java
index c63b676..36d0a21 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DeviceIdSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/DeviceIdSerializer.java
@@ -14,6 +14,14 @@
 */
 public final class DeviceIdSerializer extends Serializer<DeviceId> {
 
+    /**
+     * Creates {@link DeviceId} serializer instance.
+     */
+    public DeviceIdSerializer() {
+        // non-null, immutable
+        super(false, true);
+    }
+
     @Override
     public void write(Kryo kryo, Output output, DeviceId object) {
         kryo.writeObject(output, object.uri());
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ImmutableMapSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ImmutableMapSerializer.java
index 244cc57..734033f 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ImmutableMapSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ImmutableMapSerializer.java
@@ -19,6 +19,9 @@
 
     private final MapSerializer mapSerializer = new MapSerializer();
 
+    /**
+     * Creates {@link ImmutableMap} serializer instance.
+     */
     public ImmutableMapSerializer() {
         // non-null, immutable
         super(false, true);
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ImmutableSetSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ImmutableSetSerializer.java
index c08bf9a..051a843 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ImmutableSetSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ImmutableSetSerializer.java
@@ -18,6 +18,9 @@
 
     private final CollectionSerializer serializer = new CollectionSerializer();
 
+    /**
+     * Creates {@link ImmutableSet} serializer instance.
+     */
     public ImmutableSetSerializer() {
         // non-null, immutable
         super(false, true);
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/IpAddressSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/IpAddressSerializer.java
new file mode 100644
index 0000000..b923df7
--- /dev/null
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/IpAddressSerializer.java
@@ -0,0 +1,41 @@
+package org.onlab.onos.store.serializers;
+
+import org.onlab.packet.IpAddress;
+import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.io.Input;
+import com.esotericsoftware.kryo.io.Output;
+
+/**
+ * Kryo Serializer for {@link IpAddress}.
+ */
+public class IpAddressSerializer extends Serializer<IpAddress> {
+
+    /**
+     * Creates {@link IpAddress} serializer instance.
+     */
+    public IpAddressSerializer() {
+        // non-null, immutable
+        super(false, true);
+    }
+
+    @Override
+    public void write(Kryo kryo, Output output,
+            IpAddress object) {
+        byte[] octs = object.toOctets();
+        output.writeInt(octs.length);
+        output.writeBytes(octs);
+        output.writeInt(object.prefixLength());
+    }
+
+    @Override
+    public IpAddress read(Kryo kryo, Input input,
+            Class<IpAddress> type) {
+        int octLen = input.readInt();
+        byte[] octs = new byte[octLen];
+        input.read(octs);
+        int prefLen = input.readInt();
+        return IpAddress.valueOf(octs, prefLen);
+    }
+
+}
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/IpPrefixSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/IpPrefixSerializer.java
index 2dbec57..2e92692 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/IpPrefixSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/IpPrefixSerializer.java
@@ -13,7 +13,7 @@
 public final class IpPrefixSerializer extends Serializer<IpPrefix> {
 
     /**
-     * Default constructor.
+     * Creates {@link IpPrefix} serializer instance.
      */
     public IpPrefixSerializer() {
         // non-null, immutable
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoPoolUtil.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoPoolUtil.java
new file mode 100644
index 0000000..f1a12fe
--- /dev/null
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoPoolUtil.java
@@ -0,0 +1,79 @@
+package org.onlab.onos.store.serializers;
+
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.HashMap;
+
+import org.onlab.onos.cluster.ControllerNode;
+import org.onlab.onos.cluster.DefaultControllerNode;
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.cluster.NodeId;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultAnnotations;
+import org.onlab.onos.net.DefaultDevice;
+import org.onlab.onos.net.DefaultLink;
+import org.onlab.onos.net.DefaultPort;
+import org.onlab.onos.net.Device;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Element;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.LinkKey;
+import org.onlab.onos.net.MastershipRole;
+import org.onlab.onos.net.Port;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.IpPrefix;
+import org.onlab.util.KryoPool;
+
+import de.javakaffee.kryoserializers.URISerializer;
+
+public final class KryoPoolUtil {
+
+    /**
+     * KryoPool which can serialize ON.lab misc classes.
+     */
+    public static final KryoPool MISC = KryoPool.newBuilder()
+            .register(IpPrefix.class, new IpPrefixSerializer())
+            .register(IpAddress.class, new IpAddressSerializer())
+            .build();
+
+    // TODO: Populate other classes
+    /**
+     * KryoPool which can serialize API bundle classes.
+     */
+    public static final KryoPool API = KryoPool.newBuilder()
+            .register(MISC)
+            .register(
+                    //
+                    ArrayList.class,
+                    HashMap.class,
+                    //
+                    ControllerNode.State.class,
+                    Device.Type.class,
+                    DefaultAnnotations.class,
+                    DefaultControllerNode.class,
+                    DefaultDevice.class,
+                    MastershipRole.class,
+                    Port.class,
+                    Element.class,
+                    Link.Type.class
+                    )
+            .register(URI.class, new URISerializer())
+            .register(NodeId.class, new NodeIdSerializer())
+            .register(ProviderId.class, new ProviderIdSerializer())
+            .register(DeviceId.class, new DeviceIdSerializer())
+            .register(PortNumber.class, new PortNumberSerializer())
+            .register(DefaultPort.class, new DefaultPortSerializer())
+            .register(LinkKey.class, new LinkKeySerializer())
+            .register(ConnectPoint.class, new ConnectPointSerializer())
+            .register(DefaultLink.class, new DefaultLinkSerializer())
+            .register(MastershipTerm.class, new MastershipTermSerializer())
+            .register(MastershipRole.class, new MastershipRoleSerializer())
+
+            .build();
+
+
+    // not to be instantiated
+    private KryoPoolUtil() {}
+}
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoSerializationManager.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoSerializationManager.java
index 04d1a88..1b5cac4 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoSerializationManager.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/KryoSerializationManager.java
@@ -1,36 +1,14 @@
 package org.onlab.onos.store.serializers;
 
-import de.javakaffee.kryoserializers.URISerializer;
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
 import org.apache.felix.scr.annotations.Service;
-import org.onlab.onos.cluster.ControllerNode;
-import org.onlab.onos.cluster.DefaultControllerNode;
-import org.onlab.onos.cluster.NodeId;
-import org.onlab.onos.net.ConnectPoint;
-import org.onlab.onos.net.DefaultAnnotations;
-import org.onlab.onos.net.DefaultDevice;
-import org.onlab.onos.net.DefaultLink;
-import org.onlab.onos.net.DefaultPort;
-import org.onlab.onos.net.Device;
-import org.onlab.onos.net.DeviceId;
-import org.onlab.onos.net.Element;
-import org.onlab.onos.net.Link;
-import org.onlab.onos.net.LinkKey;
-import org.onlab.onos.net.MastershipRole;
-import org.onlab.onos.net.Port;
-import org.onlab.onos.net.PortNumber;
-import org.onlab.onos.net.provider.ProviderId;
-import org.onlab.packet.IpPrefix;
 import org.onlab.util.KryoPool;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.net.URI;
 import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.HashMap;
 
 /**
  * Serialization service using Kryo.
@@ -58,33 +36,8 @@
      * Sets up the common serialzers pool.
      */
     protected void setupKryoPool() {
-        // FIXME Slice out types used in common to separate pool/namespace.
         serializerPool = KryoPool.newBuilder()
-                .register(ArrayList.class,
-                          HashMap.class,
-
-                          ControllerNode.State.class,
-                          Device.Type.class,
-
-                          DefaultAnnotations.class,
-                          DefaultControllerNode.class,
-                          DefaultDevice.class,
-                          MastershipRole.class,
-                          Port.class,
-                          Element.class,
-
-                          Link.Type.class
-                )
-                .register(IpPrefix.class, new IpPrefixSerializer())
-                .register(URI.class, new URISerializer())
-                .register(NodeId.class, new NodeIdSerializer())
-                .register(ProviderId.class, new ProviderIdSerializer())
-                .register(DeviceId.class, new DeviceIdSerializer())
-                .register(PortNumber.class, new PortNumberSerializer())
-                .register(DefaultPort.class, new DefaultPortSerializer())
-                .register(LinkKey.class, new LinkKeySerializer())
-                .register(ConnectPoint.class, new ConnectPointSerializer())
-                .register(DefaultLink.class, new DefaultLinkSerializer())
+                .register(KryoPoolUtil.API)
                 .build()
                 .populate(1);
     }
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/LinkKeySerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/LinkKeySerializer.java
index f635f3c..bafee4f 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/LinkKeySerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/LinkKeySerializer.java
@@ -2,6 +2,7 @@
 
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.LinkKey;
+
 import com.esotericsoftware.kryo.Kryo;
 import com.esotericsoftware.kryo.Serializer;
 import com.esotericsoftware.kryo.io.Input;
@@ -13,7 +14,7 @@
 public class LinkKeySerializer extends Serializer<LinkKey> {
 
     /**
-     * Default constructor.
+     * Creates {@link LinkKey} serializer instance.
      */
     public LinkKeySerializer() {
         // non-null, immutable
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/MastershipRoleSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/MastershipRoleSerializer.java
index 3903491..dab5aa8 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/MastershipRoleSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/MastershipRoleSerializer.java
@@ -12,6 +12,14 @@
  */
 public class MastershipRoleSerializer extends Serializer<MastershipRole> {
 
+    /**
+     * Creates {@link MastershipRole} serializer instance.
+     */
+    public MastershipRoleSerializer() {
+        // non-null, immutable
+        super(false, true);
+    }
+
     @Override
     public MastershipRole read(Kryo kryo, Input input, Class<MastershipRole> type) {
         final String role = kryo.readObject(input, String.class);
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/MastershipTermSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/MastershipTermSerializer.java
index a5d6198..e4cb999 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/MastershipTermSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/MastershipTermSerializer.java
@@ -2,7 +2,6 @@
 
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.cluster.NodeId;
-
 import com.esotericsoftware.kryo.Kryo;
 import com.esotericsoftware.kryo.Serializer;
 import com.esotericsoftware.kryo.io.Input;
@@ -13,6 +12,14 @@
  */
 public class MastershipTermSerializer extends Serializer<MastershipTerm> {
 
+    /**
+     * Creates {@link MastershipTerm} serializer instance.
+     */
+    public MastershipTermSerializer() {
+        // non-null, immutable
+        super(false, true);
+    }
+
     @Override
     public MastershipTerm read(Kryo kryo, Input input, Class<MastershipTerm> type) {
         final NodeId node = new NodeId(kryo.readObject(input, String.class));
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/NodeIdSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/NodeIdSerializer.java
index ef9d3f1..57c9c16 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/NodeIdSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/NodeIdSerializer.java
@@ -4,6 +4,7 @@
 import com.esotericsoftware.kryo.Serializer;
 import com.esotericsoftware.kryo.io.Input;
 import com.esotericsoftware.kryo.io.Output;
+
 import org.onlab.onos.cluster.NodeId;
 
 /**
@@ -11,6 +12,14 @@
  */
 public final class NodeIdSerializer extends Serializer<NodeId> {
 
+    /**
+     * Creates {@link NodeId} serializer instance.
+     */
+    public NodeIdSerializer() {
+        // non-null, immutable
+        super(false, true);
+    }
+
     @Override
     public void write(Kryo kryo, Output output, NodeId object) {
         kryo.writeObject(output, object.toString());
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/PortNumberSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/PortNumberSerializer.java
index 02805bb..3792966 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/PortNumberSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/PortNumberSerializer.java
@@ -14,7 +14,7 @@
         Serializer<PortNumber> {
 
     /**
-     * Default constructor.
+     * Creates {@link PortNumber} serializer instance.
      */
     public PortNumberSerializer() {
         // non-null, immutable
diff --git a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ProviderIdSerializer.java b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ProviderIdSerializer.java
index 1a1c6f6..f546f63 100644
--- a/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ProviderIdSerializer.java
+++ b/core/store/serializers/src/main/java/org/onlab/onos/store/serializers/ProviderIdSerializer.java
@@ -13,7 +13,7 @@
 public class ProviderIdSerializer extends Serializer<ProviderId> {
 
     /**
-     * Default constructor.
+     * Creates {@link ProviderId} serializer instance.
      */
     public ProviderIdSerializer() {
         // non-null, immutable
diff --git a/core/store/serializers/src/test/java/org/onlab/onos/store/serializers/KryoSerializerTests.java b/core/store/serializers/src/test/java/org/onlab/onos/store/serializers/KryoSerializerTests.java
index c972d1a..fd05aac 100644
--- a/core/store/serializers/src/test/java/org/onlab/onos/store/serializers/KryoSerializerTests.java
+++ b/core/store/serializers/src/test/java/org/onlab/onos/store/serializers/KryoSerializerTests.java
@@ -3,16 +3,11 @@
 import static org.onlab.onos.net.DeviceId.deviceId;
 import static org.onlab.onos.net.PortNumber.portNumber;
 
-import java.net.URI;
 import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.HashMap;
-
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.cluster.NodeId;
 import org.onlab.onos.net.ConnectPoint;
 import org.onlab.onos.net.DefaultDevice;
@@ -22,7 +17,6 @@
 import org.onlab.onos.net.DeviceId;
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.LinkKey;
-import org.onlab.onos.net.MastershipRole;
 import org.onlab.onos.net.PortNumber;
 import org.onlab.onos.net.provider.ProviderId;
 import org.onlab.packet.IpPrefix;
@@ -32,8 +26,6 @@
 import com.google.common.collect.ImmutableSet;
 import com.google.common.testing.EqualsTester;
 
-import de.javakaffee.kryoserializers.URISerializer;
-
 public class KryoSerializerTests {
     private static final ProviderId PID = new ProviderId("of", "foo");
     private static final DeviceId DID1 = deviceId("of:foo");
@@ -54,38 +46,12 @@
     @BeforeClass
     public static void setUpBeforeClass() throws Exception {
         kryos = KryoPool.newBuilder()
-                .register(
-                        ArrayList.class,
-                        HashMap.class
-                        )
-                .register(
-                        Device.Type.class,
-                        Link.Type.class
-
-//                      ControllerNode.State.class,
-//                        DefaultControllerNode.class,
-//                        MastershipRole.class,
-//                        Port.class,
-//                        Element.class,
-                        )
-                .register(ConnectPoint.class, new ConnectPointSerializer())
-                .register(DefaultLink.class, new DefaultLinkSerializer())
-                .register(DefaultPort.class, new DefaultPortSerializer())
-                .register(DeviceId.class, new DeviceIdSerializer())
+                .register(KryoPoolUtil.API)
                 .register(ImmutableMap.class, new ImmutableMapSerializer())
                 .register(ImmutableSet.class, new ImmutableSetSerializer())
-                .register(IpPrefix.class, new IpPrefixSerializer())
-                .register(LinkKey.class, new LinkKeySerializer())
-                .register(NodeId.class, new NodeIdSerializer())
-                .register(PortNumber.class, new PortNumberSerializer())
-                .register(ProviderId.class, new ProviderIdSerializer())
 
-                .register(DefaultDevice.class)
 
-                .register(URI.class, new URISerializer())
 
-                .register(MastershipRole.class, new MastershipRoleSerializer())
-                .register(MastershipTerm.class, new MastershipTermSerializer())
                 .build();
     }
 
diff --git a/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/NoOpClockProviderService.java b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/NoOpClockProviderService.java
new file mode 100644
index 0000000..ff4b31a
--- /dev/null
+++ b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/NoOpClockProviderService.java
@@ -0,0 +1,20 @@
+package org.onlab.onos.store.trivial.impl;
+
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.cluster.MastershipTerm;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.ClockProviderService;
+
+//FIXME: Code clone in onos-core-trivial, onos-core-hz-net
+/**
+ * Dummy implementation of {@link ClockProviderService}.
+ */
+@Component(immediate = true)
+@Service
+public class NoOpClockProviderService implements ClockProviderService {
+
+    @Override
+    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {
+    }
+}
diff --git a/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/NoOpClockService.java b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/NoOpClockService.java
deleted file mode 100644
index b3f8320..0000000
--- a/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/NoOpClockService.java
+++ /dev/null
@@ -1,32 +0,0 @@
-package org.onlab.onos.store.trivial.impl;
-
-import org.apache.felix.scr.annotations.Component;
-import org.apache.felix.scr.annotations.Service;
-import org.onlab.onos.cluster.MastershipTerm;
-import org.onlab.onos.net.DeviceId;
-import org.onlab.onos.store.ClockService;
-import org.onlab.onos.store.Timestamp;
-
-//FIXME: Code clone in onos-core-trivial, onos-core-hz-net
-/**
- * Dummy implementation of {@link ClockService}.
- */
-@Component(immediate = true)
-@Service
-public class NoOpClockService implements ClockService {
-
-    @Override
-    public Timestamp getTimestamp(DeviceId deviceId) {
-        return new Timestamp() {
-
-            @Override
-            public int compareTo(Timestamp o) {
-                throw new IllegalStateException("Never expected to be used.");
-            }
-        };
-    }
-
-    @Override
-    public void setMastershipTerm(DeviceId deviceId, MastershipTerm term) {
-    }
-}
diff --git a/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleIntentStore.java b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleIntentStore.java
new file mode 100644
index 0000000..4143548
--- /dev/null
+++ b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleIntentStore.java
@@ -0,0 +1,107 @@
+package org.onlab.onos.store.trivial.impl;
+
+import static org.onlab.onos.net.intent.IntentState.COMPILED;
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.net.intent.InstallableIntent;
+import org.onlab.onos.net.intent.Intent;
+import org.onlab.onos.net.intent.IntentEvent;
+import org.onlab.onos.net.intent.IntentId;
+import org.onlab.onos.net.intent.IntentState;
+import org.onlab.onos.net.intent.IntentStore;
+import org.onlab.onos.net.intent.IntentStoreDelegate;
+import org.onlab.onos.store.AbstractStore;
+import org.slf4j.Logger;
+
+import com.google.common.collect.ImmutableSet;
+
+@Component(immediate = true)
+@Service
+public class SimpleIntentStore
+    extends AbstractStore<IntentEvent, IntentStoreDelegate>
+    implements IntentStore {
+
+    private final Logger log = getLogger(getClass());
+    private final Map<IntentId, Intent> intents = new HashMap<>();
+    private final Map<IntentId, IntentState> states = new HashMap<>();
+    private final Map<IntentId, List<InstallableIntent>> installable = new HashMap<>();
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+
+    @Override
+    public IntentEvent createIntent(Intent intent) {
+        intents.put(intent.getId(), intent);
+        return this.setState(intent, IntentState.SUBMITTED);
+    }
+
+    @Override
+    public IntentEvent removeIntent(IntentId intentId) {
+        Intent intent = intents.remove(intentId);
+        installable.remove(intentId);
+        IntentEvent event = this.setState(intent, IntentState.WITHDRAWN);
+        states.remove(intentId);
+        return event;
+    }
+
+    @Override
+    public long getIntentCount() {
+        return intents.size();
+    }
+
+    @Override
+    public Iterable<Intent> getIntents() {
+        return ImmutableSet.copyOf(intents.values());
+    }
+
+    @Override
+    public Intent getIntent(IntentId intentId) {
+        return intents.get(intentId);
+    }
+
+    @Override
+    public IntentState getIntentState(IntentId id) {
+        return states.get(id);
+    }
+
+    // TODO return dispatch event here... replace with state transition methods
+    @Override
+    public IntentEvent setState(Intent intent, IntentState newState) {
+        IntentId id = intent.getId();
+        IntentState oldState = states.get(id);
+        states.put(id, newState);
+        return new IntentEvent(intent, newState, oldState, System.currentTimeMillis());
+    }
+
+    @Override
+    public IntentEvent addInstallableIntents(IntentId intentId, List<InstallableIntent> result) {
+        installable.put(intentId, result);
+        return this.setState(intents.get(intentId), COMPILED);
+    }
+
+    @Override
+    public List<InstallableIntent> getInstallableIntents(IntentId intentId) {
+        return installable.get(intentId);
+    }
+
+    @Override
+    public void removeInstalledIntents(IntentId intentId) {
+        installable.remove(intentId);
+    }
+
+}
diff --git a/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleLinkStore.java b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleLinkStore.java
index a0e569d..6b96bc7 100644
--- a/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleLinkStore.java
+++ b/core/store/trivial/src/main/java/org/onlab/onos/store/trivial/impl/SimpleLinkStore.java
@@ -32,6 +32,7 @@
 import static org.onlab.onos.net.link.LinkEvent.Type.*;
 import static org.slf4j.LoggerFactory.getLogger;
 
+// TODO: Add support for multiple provider and annotations
 /**
  * Manages inventory of infrastructure links using trivial in-memory structures
  * implementation.
diff --git a/pom.xml b/pom.xml
index cb00f32..665d1b0 100644
--- a/pom.xml
+++ b/pom.xml
@@ -480,7 +480,7 @@
                         <group>
                             <title>Core Subsystems</title>
                             <packages>
-                                org.onlab.onos.cluster.impl:org.onlab.onos.net.device.impl:org.onlab.onos.net.link.impl:org.onlab.onos.net.host.impl:org.onlab.onos.net.topology.impl:org.onlab.onos.net.packet.impl:org.onlab.onos.net.flow.impl:org.onlab.onos.store.trivial.*:org.onlab.onos.net.*.impl:org.onlab.onos.event.impl:org.onlab.onos.store.*
+                                org.onlab.onos.cluster.impl:org.onlab.onos.net.device.impl:org.onlab.onos.net.link.impl:org.onlab.onos.net.host.impl:org.onlab.onos.net.topology.impl:org.onlab.onos.net.packet.impl:org.onlab.onos.net.flow.impl:org.onlab.onos.store.trivial.*:org.onlab.onos.net.*.impl:org.onlab.onos.event.impl:org.onlab.onos.store.*:org.onlab.onos.net.intent.impl
                             </packages>
                         </group>
                         <group>
diff --git a/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/FlowRuleBuilder.java b/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/FlowRuleBuilder.java
index f3655f7..876bc27 100644
--- a/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/FlowRuleBuilder.java
+++ b/providers/openflow/flow/src/main/java/org/onlab/onos/provider/of/flow/impl/FlowRuleBuilder.java
@@ -113,7 +113,7 @@
     }
 
     private TrafficTreatment buildTreatment() {
-        TrafficTreatment.Builder builder = new DefaultTrafficTreatment.Builder();
+        TrafficTreatment.Builder builder = DefaultTrafficTreatment.builder();
         // If this is a drop rule
         if (actions.size() == 0) {
             builder.drop();
@@ -198,7 +198,7 @@
     }
 
     private TrafficSelector buildSelector() {
-        TrafficSelector.Builder builder = new DefaultTrafficSelector.Builder();
+        TrafficSelector.Builder builder = DefaultTrafficSelector.builder();
         for (MatchField<?> field : match.getMatchFields()) {
             switch (field.id) {
             case IN_PORT:
diff --git a/providers/openflow/packet/src/test/java/org/onlab/onos/provider/of/packet/impl/OpenFlowPacketProviderTest.java b/providers/openflow/packet/src/test/java/org/onlab/onos/provider/of/packet/impl/OpenFlowPacketProviderTest.java
index 030563c..37971e3 100644
--- a/providers/openflow/packet/src/test/java/org/onlab/onos/provider/of/packet/impl/OpenFlowPacketProviderTest.java
+++ b/providers/openflow/packet/src/test/java/org/onlab/onos/provider/of/packet/impl/OpenFlowPacketProviderTest.java
@@ -181,7 +181,7 @@
     }
 
     private static TrafficTreatment treatment(Instruction ... insts) {
-        TrafficTreatment.Builder builder = new DefaultTrafficTreatment.Builder();
+        TrafficTreatment.Builder builder = DefaultTrafficTreatment.builder();
         for (Instruction i : insts) {
             builder.add(i);
         }
diff --git a/tools/dev/bash_profile b/tools/dev/bash_profile
index 8332a47..3d80228 100644
--- a/tools/dev/bash_profile
+++ b/tools/dev/bash_profile
@@ -21,7 +21,7 @@
 # e.g. 'o api', 'o dev', 'o'
 function o {
     cd $(find $ONOS_ROOT/ -type d | egrep -v '\.git|target' | \
-        egrep "${1:-$ONOS_ROOT}" | head -n 1)
+        egrep "${1:-$ONOS_ROOT}" | egrep -v "$ONOS_ROOT/.+/src/" | head -n 1)
 }
 
 # Short-hand for 'mvn clean install' for us lazy folk
diff --git a/utils/misc/src/main/java/org/onlab/metrics/MetricsFeature.java b/utils/misc/src/main/java/org/onlab/metrics/MetricsFeature.java
index 7a97b08..75c1018 100644
--- a/utils/misc/src/main/java/org/onlab/metrics/MetricsFeature.java
+++ b/utils/misc/src/main/java/org/onlab/metrics/MetricsFeature.java
@@ -11,7 +11,7 @@
      *
      * @param newName name of the Feature
      */
-    MetricsFeature(final String newName) {
+    public MetricsFeature(final String newName) {
         name = newName;
     }
 
diff --git a/utils/netty/src/main/java/org/onlab/netty/SimpleClient.java b/utils/netty/src/main/java/org/onlab/netty/SimpleClient.java
index 1573780..5ce8f2e 100644
--- a/utils/netty/src/main/java/org/onlab/netty/SimpleClient.java
+++ b/utils/netty/src/main/java/org/onlab/netty/SimpleClient.java
@@ -2,16 +2,43 @@
 
 import java.util.concurrent.TimeUnit;
 
+import org.onlab.metrics.MetricsComponent;
+import org.onlab.metrics.MetricsFeature;
+import org.onlab.metrics.MetricsManager;
+
+import com.codahale.metrics.Timer;
+
 public final class SimpleClient {
-    private SimpleClient() {}
+    private SimpleClient() {
+    }
 
     public static void main(String... args) throws Exception {
         NettyMessagingService messaging = new TestNettyMessagingService(9081);
+        MetricsManager metrics = new MetricsManager();
         messaging.activate();
+        metrics.activate();
+        MetricsFeature feature = new MetricsFeature("timers");
+        MetricsComponent component = metrics.registerComponent("NettyMessaging");
+        Timer sendAsyncTimer = metrics.createTimer(component, feature, "AsyncSender");
+        final int warmup = 100;
+        for (int i = 0; i < warmup; i++) {
+            Timer.Context context = sendAsyncTimer.time();
+            messaging.sendAsync(new Endpoint("localhost", 8080), "simple", "Hello World");
+            context.stop();
+        }
+        metrics.registerMetric(component, feature, "AsyncTimer", sendAsyncTimer);
 
-        messaging.sendAsync(new Endpoint("localhost", 8080), "simple", "Hello World");
-        Response<String> response = messaging.sendAndReceive(new Endpoint("localhost", 8080), "echo", "Hello World");
-        System.out.println("Got back:" + response.get(2, TimeUnit.SECONDS));
+        Timer sendAndReceiveTimer = metrics.createTimer(component, feature, "SendAndReceive");
+        final int iterations = 1000000;
+        for (int i = 0; i < iterations; i++) {
+            Timer.Context context = sendAndReceiveTimer.time();
+            Response<String> response = messaging
+                    .sendAndReceive(new Endpoint("localhost", 8080), "echo",
+                                    "Hello World");
+            System.out.println("Got back:" + response.get(2, TimeUnit.SECONDS));
+            context.stop();
+        }
+        metrics.registerMetric(component, feature, "AsyncTimer", sendAndReceiveTimer);
     }
 
     public static class TestNettyMessagingService extends NettyMessagingService {