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/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
index ff6e7c6..08063f0 100644
--- 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
@@ -1,17 +1,16 @@
 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.HostId;
 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.
+ * Abstraction of end-station to end-station connectivity.
  */
 public class HostToHostIntent extends ConnectivityIntent {
 
@@ -22,17 +21,15 @@
      * Creates a new point-to-point intent with the supplied ingress/egress
      * ports.
      *
-     * @param id intent identifier
-     * @param match traffic match
-     * @param action action
-     * @param ingressPort ingress port
-     * @param egressPort egress port
+     * @param intentId  intent identifier
+     * @param selector  action
+     * @param treatment ingress port
      * @throws NullPointerException if {@code ingressPort} or {@code egressPort}
-     *         is null.
+     *                              is null.
      */
-    public HostToHostIntent(IntentId id, HostId src, HostId dst,
-            TrafficSelector selector, TrafficTreatment treatment) {
-        super(id, selector, treatment);
+    public HostToHostIntent(IntentId intentId, HostId src, HostId dst,
+                            TrafficSelector selector, TrafficTreatment treatment) {
+        super(intentId, selector, treatment);
         this.src = checkNotNull(src);
         this.dst = checkNotNull(dst);
     }
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 b8f0344..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
@@ -1,12 +1,11 @@
 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 org.onlab.onos.event.AbstractEvent;
-
-import com.google.common.base.MoreObjects;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * A class to represent an intent related event.
@@ -24,10 +23,10 @@
     /**
      * 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) {
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/IntentService.java b/core/api/src/main/java/org/onlab/onos/net/intent/IntentService.java
index 8d550e8..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
@@ -7,7 +7,7 @@
 public interface IntentService {
     /**
      * Submits an intent into the system.
-     *
+     * <p/>
      * This is an asynchronous request meaning that any compiling or
      * installation activities may be done at later time.
      *
@@ -17,7 +17,7 @@
 
     /**
      * Withdraws an intent from the system.
-     *
+     * <p/>
      * This is an asynchronous request meaning that the environment may be
      * affected at later time.
      *
@@ -28,7 +28,7 @@
     /**
      * Submits a batch of submit &amp; withdraw operations. Such a batch is
      * assumed to be processed together.
-     *
+     * <p/>
      * This is an asynchronous request meaning that the environment may be
      * affected at later time.
      *
@@ -63,7 +63,7 @@
      *
      * @param id intent identifier
      * @return the intent state or null if one with the given identifier is not
-     *         found
+     * found
      */
     IntentState getIntentState(IntentId id);
 
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
index 792398e..037f179 100644
--- 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
@@ -1,9 +1,9 @@
 package org.onlab.onos.net.intent;
 
-import java.util.List;
-
 import org.onlab.onos.store.Store;
 
+import java.util.List;
+
 /**
  * Manages inventory of end-station intents; not intended for direct use.
  */
@@ -21,13 +21,12 @@
      * Removes the specified intent from the inventory.
      *
      * @param intentId intent identification
-     * @return remove event or null if intent was not found
+     * @return removed state transition event or null if intent was not found
      */
-    IntentEvent removeIntent(IntentId intent);
+    IntentEvent removeIntent(IntentId intentId);
 
     /**
      * Returns the number of intents in the store.
-     *
      */
     long getIntentCount();
 
@@ -46,19 +45,52 @@
      */
     Intent getIntent(IntentId intentId);
 
-    IntentState getIntentState(IntentId id);
+    /**
+     * 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 intent   intent whose state is to be changed
      * @param newState new state
+     * @return state transition event
      */
     IntentEvent setState(Intent intent, IntentState newState);
 
-    IntentEvent addInstallableIntents(IntentId intentId, List<InstallableIntent> result);
+    /**
+     * 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
index 5a4da1a..6c37db8 100644
--- 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
@@ -3,7 +3,7 @@
 import org.onlab.onos.store.StoreDelegate;
 
 /**
- * Infrastructure link store delegate abstraction.
+ * 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/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/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;
     }