diff --git a/src/main/java/net/onrc/onos/apps/forwarding/Forwarding.java b/src/main/java/net/onrc/onos/apps/forwarding/Forwarding.java
index d955828..03c9740 100644
--- a/src/main/java/net/onrc/onos/apps/forwarding/Forwarding.java
+++ b/src/main/java/net/onrc/onos/apps/forwarding/Forwarding.java
@@ -560,6 +560,8 @@
                     break;
                 case STATE_CHANGED:
                     IntentState state = pathIntent.getState();
+                    log.debug("This is STATE_CHANGED. intent id {} is now state {}",
+                            pathIntent.getId() , state);
                     switch (state) {
                         case INST_REQ:
                             break;
diff --git a/src/main/java/net/onrc/onos/core/devicemanager/OnosDevice.java b/src/main/java/net/onrc/onos/core/devicemanager/OnosDevice.java
index d0a5ee4..1a2bdeb 100644
--- a/src/main/java/net/onrc/onos/core/devicemanager/OnosDevice.java
+++ b/src/main/java/net/onrc/onos/core/devicemanager/OnosDevice.java
@@ -19,9 +19,12 @@
 
 import java.io.Serializable;
 import java.util.Date;
+import java.util.Objects;
 
 import net.floodlightcontroller.util.MACAddress;
 
+
+
 /**
  * An entity on the network is a visible trace of a device that corresponds
  * to a packet received from a particular interface on the edge of a network,
@@ -53,13 +56,13 @@
      * The DPID of the switch for the ingress point for this entity,
      * or null if not present.
      */
-    private long switchDPID;
+    private Long switchDPID;
 
     /**
      * The port number of the switch for the ingress point for this entity,
      * or null if not present.
      */
-    private short switchPort;
+    private Long switchPort;
 
     /**
      * The last time we observed this entity on the network.
@@ -75,16 +78,16 @@
     }
 
     /**
-     * Create a new entity.
+     * Create a new device and its information.
      *
-     * @param macAddress
-     * @param vlan
-     * @param switchDPID
-     * @param switchPort
-     * @param lastSeenTimestamp
+     * @param macAddress mac address of this device
+     * @param vlan vlan ID of this device
+     * @param switchDPID switch DPID where the device is attached
+     * @param switchPort port number where the device is attached
+     * @param lastSeenTimestamp last packet-in time of this device
      */
     public OnosDevice(MACAddress macAddress, Short vlan, Long switchDPID,
-            short switchPort, Date lastSeenTimestamp) {
+            Long switchPort, Date lastSeenTimestamp) {
         this.macAddress = macAddress;
         this.vlan = vlan;
         this.switchDPID = switchDPID;
@@ -112,18 +115,10 @@
         return switchDPID;
     }
 
-    public void setSwitchDPID(long dpid) {
-        this.switchDPID = dpid;
-    }
-
-    public short getSwitchPort() {
+    public Long getSwitchPort() {
         return switchPort;
     }
 
-    public void setSwitchPort(short port) {
-        this.switchPort = port;
-    }
-
     public Date getLastSeenTimestamp() {
         if (this.lastSeenTimestamp == null) {
             return null;
@@ -137,14 +132,11 @@
 
     @Override
     public int hashCode() {
-        if (hashCode != 0) {
-            return hashCode;
-        }
         final int prime = 31;
         hashCode = 1;
         hashCode = prime * hashCode + (int) (macAddress.toLong() ^ (macAddress.toLong() >>> 32));
-        hashCode = prime * hashCode + (int) switchDPID;
-        hashCode = prime * hashCode + (int) switchPort;
+        hashCode = prime * hashCode + ((switchDPID == null) ? 0 : switchDPID.hashCode());
+        hashCode = prime * hashCode + ((switchPort == null) ? 0 : switchPort.hashCode());
         hashCode = prime * hashCode + ((vlan == null) ? 0 : vlan.hashCode());
         return hashCode;
     }
@@ -164,24 +156,16 @@
         if (hashCode() != other.hashCode()) {
             return false;
         }
-        if (macAddress == null) {
-            if (other.macAddress != null) {
-                return false;
-            }
-        } else if (!macAddress.equals(other.macAddress)) {
+        if (!Objects.equals(macAddress, other.macAddress)) {
             return false;
         }
-        if (switchDPID != other.switchDPID) {
+        if (!Objects.equals(switchDPID, other.switchDPID)) {
             return false;
         }
-        if (switchPort != other.switchPort) {
+        if (!Objects.equals(switchPort, other.switchPort)) {
             return false;
         }
-        if (vlan == null) {
-            if (other.vlan != null) {
-                return false;
-            }
-        } else if (!vlan.equals(other.vlan)) {
+        if (!Objects.equals(vlan, other.vlan)) {
             return false;
         }
         return true;
diff --git a/src/main/java/net/onrc/onos/core/devicemanager/OnosDeviceManager.java b/src/main/java/net/onrc/onos/core/devicemanager/OnosDeviceManager.java
index 23944a0..0c7a75e 100644
--- a/src/main/java/net/onrc/onos/core/devicemanager/OnosDeviceManager.java
+++ b/src/main/java/net/onrc/onos/core/devicemanager/OnosDeviceManager.java
@@ -8,7 +8,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
@@ -24,11 +23,10 @@
 import net.floodlightcontroller.core.module.IFloodlightModule;
 import net.floodlightcontroller.core.module.IFloodlightService;
 import net.floodlightcontroller.util.MACAddress;
-import net.onrc.onos.core.datagrid.IDatagridService;
-import net.onrc.onos.core.datagrid.IEventChannel;
-import net.onrc.onos.core.datagrid.IEventChannelListener;
 import net.onrc.onos.core.packet.Ethernet;
+import net.onrc.onos.core.topology.Device;
 import net.onrc.onos.core.topology.ITopologyService;
+import net.onrc.onos.core.topology.Port;
 import net.onrc.onos.core.topology.Topology;
 
 import org.openflow.protocol.OFMessage;
@@ -39,8 +37,7 @@
 
 public class OnosDeviceManager implements IFloodlightModule,
         IOFMessageListener,
-        IOnosDeviceService,
-        IEventChannelListener<Long, OnosDevice> {
+        IOnosDeviceService {
 
     private static final Logger log = LoggerFactory.getLogger(OnosDeviceManager.class);
     private static final long DEVICE_CLEANING_INITIAL_DELAY = 30;
@@ -52,16 +49,6 @@
     private static final ScheduledExecutorService EXECUTOR_SERVICE =
             Executors.newSingleThreadScheduledExecutor();
 
-    // TODO This infrastructure maintains a global device cache in the
-    // OnosDeviceManager module on each instance (in mapDevice). We want to
-    // remove this eventually - the global cache should be maintained by the
-    // topology layer (which it currently is as well).
-    private IDatagridService datagrid;
-    private IEventChannel<Long, OnosDevice> eventChannel;
-    private static final String DEVICE_CHANNEL_NAME = "onos.device";
-    private final Map<Long, OnosDevice> mapDevice =
-            new ConcurrentHashMap<Long, OnosDevice>();
-
     private ITopologyService topologyService;
     private Topology topology;
 
@@ -129,6 +116,10 @@
     // The above "receive" method couldn't be tested
     // because of IFloodlightProviderService static final field.
     protected Command processPacketIn(IOFSwitch sw, OFPacketIn pi, Ethernet eth) {
+        if (log.isTraceEnabled()) {
+            log.trace("Receive PACKET_IN swId {}, portId {}", sw.getId(), pi.getInPort());
+        }
+
         long dpid = sw.getId();
         short portId = pi.getInPort();
         Long mac = eth.getSourceMAC().toLong();
@@ -140,31 +131,21 @@
             return Command.STOP;
         }
 
-        // We check if it is the same device in datagrid to suppress the device update
-        OnosDevice exDev = mapDevice.get(mac);
-        if (exDev != null && exDev.equals(srcDevice)) {
-            // There is the same existing device. Update only ActiveSince time.
-            // TODO This doesn't update the timestamp in the Topology module,
-            // only in the local cache in this local driver module.
-            exDev.setLastSeenTimestamp(new Date());
-            if (log.isTraceEnabled()) {
-                log.trace("In the local cache, there is the same device."
-                        + " Only update last seen time: {}", exDev);
-            }
-            return Command.CONTINUE;
-        }
-
         // If the switch port we try to attach a new device already has a link,
         // then don't add the device
         // TODO We probably don't need to check this here, it should be done in
         // the Topology module.
-        if (topology.getOutgoingLink(dpid, (long) portId) != null) {
-            if (log.isTraceEnabled()) {
-                log.trace("Stop adding OnosDevice {} as " +
-                        "there is a link on the port: dpid {} port {}",
-                        srcDevice.getMacAddress(), dpid, portId);
+        topology.acquireReadLock();
+        try {
+            if (topology.getOutgoingLink(dpid, (long) portId) != null ||
+                    topology.getIncomingLink(dpid, (long) portId) != null) {
+                log.debug("Stop adding OnosDevice {} as " +
+                    "there is a link on the port: dpid {} port {}",
+                    srcDevice.getMacAddress(), dpid, portId);
+                return Command.CONTINUE;
             }
-            return Command.CONTINUE;
+        } finally {
+            topology.releaseReadLock();
         }
 
         addOnosDevice(mac, srcDevice);
@@ -187,28 +168,30 @@
         @Override
         public void run() {
             log.debug("called CleanDevice");
+            topology.acquireReadLock();
             try {
-                Set<OnosDevice> deleteSet = new HashSet<OnosDevice>();
-                for (OnosDevice dev : mapDevice.values()) {
-                    long now = new Date().getTime();
-                    if ((now - dev.getLastSeenTimestamp().getTime()
-                            > agingMillisecConfig)) {
+                Set<Device> deleteSet = new HashSet<Device>();
+                for (Device dev : topology.getDevices()) {
+                    long now = System.currentTimeMillis();
+                    if ((now - dev.getLastSeenTime() > agingMillisecConfig)) {
                         if (log.isTraceEnabled()) {
-                            log.debug("Removing device info from the datagrid: {}, diff {}",
-                                    dev, now - dev.getLastSeenTimestamp().getTime());
+                            log.trace("Removing device info: mac {}, now {}, lastSeenTime {}, diff {}",
+                                    dev.getMacAddress(), now, dev.getLastSeenTime(), now - dev.getLastSeenTime());
                         }
                         deleteSet.add(dev);
                     }
                 }
 
-                for (OnosDevice dev : deleteSet) {
-                    deleteOnosDevice(dev);
+                for (Device dev : deleteSet) {
+                    deleteOnosDeviceByMac(dev.getMacAddress());
                 }
             } catch (Exception e) {
                 // Any exception thrown by the task will prevent the Executor
                 // from running the next iteration, so we need to catch and log
                 // all exceptions here.
                 log.error("Exception in device cleanup thread:", e);
+            } finally {
+                topology.releaseReadLock();
             }
         }
     }
@@ -223,7 +206,7 @@
      */
     protected OnosDevice getSourceDeviceFromPacket(Ethernet eth,
             long swdpid,
-            short port) {
+            long port) {
         MACAddress sourceMac = eth.getSourceMAC();
 
         // Ignore broadcast/multicast source
@@ -261,7 +244,6 @@
                 new ArrayList<Class<? extends IFloodlightService>>();
         dependencies.add(IFloodlightProviderService.class);
         dependencies.add(ITopologyService.class);
-        dependencies.add(IDatagridService.class);
         return dependencies;
     }
 
@@ -270,7 +252,6 @@
             throws FloodlightModuleException {
         floodlightProvider = context.getServiceImpl(IFloodlightProviderService.class);
         deviceListeners = new CopyOnWriteArrayList<IOnosDeviceListener>();
-        datagrid = context.getServiceImpl(IDatagridService.class);
         topologyService = context.getServiceImpl(ITopologyService.class);
         topology = topologyService.getTopology();
 
@@ -280,56 +261,48 @@
     @Override
     public void startUp(FloodlightModuleContext context) {
         floodlightProvider.addOFMessageListener(OFType.PACKET_IN, this);
-        eventChannel = datagrid.addListener(DEVICE_CHANNEL_NAME, this,
-                Long.class,
-                OnosDevice.class);
         EXECUTOR_SERVICE.scheduleAtFixedRate(new CleanDevice(),
                 DEVICE_CLEANING_INITIAL_DELAY, cleanupSecondConfig, TimeUnit.SECONDS);
     }
 
     @Override
     public void deleteOnosDevice(OnosDevice dev) {
-        Long mac = dev.getMacAddress().toLong();
-        eventChannel.removeEntry(mac);
         floodlightProvider.publishUpdate(
                 new OnosDeviceUpdate(dev, OnosDeviceUpdateType.DELETE));
     }
 
     @Override
     public void deleteOnosDeviceByMac(MACAddress mac) {
-        OnosDevice deleteDevice = mapDevice.get(mac.toLong());
-        deleteOnosDevice(deleteDevice);
+        OnosDevice deleteDevice = null;
+        topology.acquireReadLock();
+        try {
+            Device dev = topology.getDeviceByMac(mac);
+
+            for (Port switchPort : dev.getAttachmentPoints()) {
+                // We don't handle vlan now and multiple attachment points.
+                deleteDevice = new OnosDevice(dev.getMacAddress(),
+                        null,
+                        switchPort.getDpid(),
+                        switchPort.getNumber(),
+                        new Date(dev.getLastSeenTime()));
+                break;
+            }
+        } finally {
+            topology.releaseReadLock();
+        }
+
+        if (deleteDevice != null) {
+            deleteOnosDevice(deleteDevice);
+        }
     }
 
     @Override
     public void addOnosDevice(Long mac, OnosDevice dev) {
-        eventChannel.addEntry(mac, dev);
         floodlightProvider.publishUpdate(
                 new OnosDeviceUpdate(dev, OnosDeviceUpdateType.ADD));
     }
 
     @Override
-    public void entryAdded(OnosDevice dev) {
-        Long mac = dev.getMacAddress().toLong();
-        mapDevice.put(mac, dev);
-        log.debug("Device added into local Cache: device mac {}", mac);
-    }
-
-    @Override
-    public void entryRemoved(OnosDevice dev) {
-        Long mac = dev.getMacAddress().toLong();
-        mapDevice.remove(mac);
-        log.debug("Device removed into local Cache: device mac {}", mac);
-    }
-
-    @Override
-    public void entryUpdated(OnosDevice dev) {
-        Long mac = dev.getMacAddress().toLong();
-        mapDevice.put(mac, dev);
-        log.debug("Device updated into local Cache: device mac {}", mac);
-    }
-
-    @Override
     public void addOnosDeviceListener(IOnosDeviceListener listener) {
         deviceListeners.add(listener);
     }
diff --git a/src/main/java/net/onrc/onos/core/intent/runtime/PlanInstallModule.java b/src/main/java/net/onrc/onos/core/intent/runtime/PlanInstallModule.java
index b74514c..025b6d7 100644
--- a/src/main/java/net/onrc/onos/core/intent/runtime/PlanInstallModule.java
+++ b/src/main/java/net/onrc/onos/core/intent/runtime/PlanInstallModule.java
@@ -340,7 +340,8 @@
                 states.domainSwitchDpids.addAll(domainSwitchDpids);
             }
             parentIntentMap.remove(intentParentId);
-            log.debug("addEntry to intentStateChannel intentId {}, states {}", flowRemovedMsg.getCookie(), states);
+            log.debug("addEntry to intentStateChannel intentId {}, states {}",
+                    pathIntentId, newState);
 
             intentStateChannel.addTransientEntry(flowRemovedMsg.getCookie(), states);
         }
diff --git a/src/main/java/net/onrc/onos/core/topology/DeviceImpl.java b/src/main/java/net/onrc/onos/core/topology/DeviceImpl.java
index fc1628e..0ba23dd 100644
--- a/src/main/java/net/onrc/onos/core/topology/DeviceImpl.java
+++ b/src/main/java/net/onrc/onos/core/topology/DeviceImpl.java
@@ -47,19 +47,19 @@
     /**
      * Only {@link TopologyManager} should use this method.
      *
-     * @param p
+     * @param port the port that the device is attached to
      */
-    void addAttachmentPoint(Port p) {
-        this.attachmentPoints.remove(p);
-        this.attachmentPoints.addFirst(p);
+    void addAttachmentPoint(Port port) {
+        this.attachmentPoints.remove(port);
+        this.attachmentPoints.addFirst(port);
     }
 
     /**
      * Only {@link TopologyManager} should use this method.
      *
-     * @param p
+     * @param port the port that the device is attached to
      */
-    boolean removeAttachmentPoint(Port p) {
-        return this.attachmentPoints.remove(p);
+    boolean removeAttachmentPoint(Port port) {
+        return this.attachmentPoints.remove(port);
     }
 }
diff --git a/src/main/java/net/onrc/onos/core/topology/TopologyManager.java b/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
index 8e0a4e6..343102b 100644
--- a/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
+++ b/src/main/java/net/onrc/onos/core/topology/TopologyManager.java
@@ -1085,6 +1085,8 @@
             attachmentFound = true;
         }
 
+        deviceImpl.setLastSeenTime(deviceEvent.getLastSeenTime());
+
         // Update the device in the topology
         if (attachmentFound) {
             log.debug("Storing the device info into the Topology: mac {}", deviceEvent.getMac());
diff --git a/src/main/java/net/onrc/onos/core/topology/TopologyPublisher.java b/src/main/java/net/onrc/onos/core/topology/TopologyPublisher.java
index 36399bc..eb76c1e 100644
--- a/src/main/java/net/onrc/onos/core/topology/TopologyPublisher.java
+++ b/src/main/java/net/onrc/onos/core/topology/TopologyPublisher.java
@@ -307,8 +307,7 @@
     public void onosDeviceAdded(OnosDevice device) {
         log.debug("Called onosDeviceAdded mac {}", device.getMacAddress());
 
-        SwitchPort sp = new SwitchPort(device.getSwitchDPID(),
-                (long) device.getSwitchPort());
+        SwitchPort sp = new SwitchPort(device.getSwitchDPID(), device.getSwitchPort());
         List<SwitchPort> spLists = new ArrayList<SwitchPort>();
         spLists.add(sp);
         DeviceEvent event = new DeviceEvent(device.getMacAddress());
diff --git a/src/test/java/net/onrc/onos/core/devicemanager/OnosDeviceManagerTest.java b/src/test/java/net/onrc/onos/core/devicemanager/OnosDeviceManagerTest.java
index 0b9defb..22900cc 100644
--- a/src/test/java/net/onrc/onos/core/devicemanager/OnosDeviceManagerTest.java
+++ b/src/test/java/net/onrc/onos/core/devicemanager/OnosDeviceManagerTest.java
@@ -7,7 +7,6 @@
 import static org.easymock.EasyMock.expect;
 import static org.easymock.EasyMock.expectLastCall;
 import static org.easymock.EasyMock.replay;
-import static org.easymock.EasyMock.verify;
 
 import java.util.Date;
 
@@ -16,12 +15,12 @@
 import net.floodlightcontroller.core.IOFSwitch;
 import net.floodlightcontroller.core.IUpdate;
 import net.floodlightcontroller.core.module.FloodlightModuleContext;
+import net.floodlightcontroller.core.module.FloodlightModuleException;
 import net.floodlightcontroller.test.FloodlightTestCase;
 import net.floodlightcontroller.util.MACAddress;
 import net.onrc.onos.core.datagrid.IDatagridService;
 import net.onrc.onos.core.datagrid.IEventChannel;
 import net.onrc.onos.core.datagrid.IEventChannelListener;
-import net.onrc.onos.core.intent.MockTopology;
 import net.onrc.onos.core.packet.ARP;
 import net.onrc.onos.core.packet.DHCP;
 import net.onrc.onos.core.packet.Data;
@@ -32,6 +31,7 @@
 import net.onrc.onos.core.registry.IControllerRegistryService;
 import net.onrc.onos.core.topology.ITopologyListener;
 import net.onrc.onos.core.topology.ITopologyService;
+import net.onrc.onos.core.topology.MockTopology;
 
 import org.easymock.EasyMock;
 import org.junit.After;
@@ -51,9 +51,9 @@
     private IPacket pkt0, pkt1, pkt2, pkt3, pkt4;
     private IOFSwitch sw1;
     private long sw1Dpid;
-    private short sw1DevPort;
+    private long sw1DevPort, sw1DevPort2;
     private OnosDeviceManager odm;
-    private OFPacketIn pktIn;
+    private OFPacketIn pktIn, pktIn2;
     private FloodlightModuleContext modContext;
     private ITopologyService networkGraphService;
     private IEventChannel<Long, OnosDevice> eventChannel;
@@ -69,7 +69,7 @@
         IDatagridService datagridService;
         IControllerRegistryService controllerRegistryService;
 
-        topology.createSampleTopology1();
+        topology.createSampleTopology2();
         modContext = new FloodlightModuleContext();
 
         floodLightProvider = createMock(IFloodlightProviderService.class);
@@ -104,6 +104,7 @@
         replay(sw1);
 
         sw1DevPort = 100;
+        sw1DevPort2 = 12L;
 
         odm = new OnosDeviceManager();
         /*
@@ -201,13 +202,11 @@
                 .setTargetProtocolAddress(IPv4.toIPv4AddressBytes("192.168.1.2")));
 
 
-        this.pktIn = new OFPacketIn()
-        .setInPort(sw1DevPort);
+        this.pktIn = new OFPacketIn().setInPort((short) sw1DevPort);
+
+        this.pktIn2 = new OFPacketIn().setInPort((short) sw1DevPort2);
 
         lastSeenTimestamp = new Date(1);
-
-        odm.init(modContext);
-        odm.startUp(modContext);
     }
 
     @Override
@@ -264,30 +263,46 @@
 
     /**
      * This test will invoke addOnosDevice to add a new device through Packet pkt1.
+     * @throws FloodlightModuleException
      */
     @Test
-    public void testProcessPacketInAddNewDevice() {
-        Ethernet eth = (Ethernet) pkt1;
-        Long longmac = eth.getSourceMAC().toLong();
-        OnosDevice srcDevice = odm.getSourceDeviceFromPacket(eth, sw1Dpid, sw1DevPort);
-
-        floodLightProvider.addOFMessageListener(EasyMock.eq(OFType.PACKET_IN), EasyMock.isA(OnosDeviceManager.class));
-        EasyMock.expectLastCall();
-        eventChannel.addEntry(longmac, srcDevice);
+    public void testProcessPacketInAddNewDevice() throws FloodlightModuleException {
+        floodLightProvider.addOFMessageListener(EasyMock.eq(OFType.PACKET_IN),
+                EasyMock.isA(OnosDeviceManager.class));
         EasyMock.expectLastCall();
         floodLightProvider.publishUpdate(EasyMock.isA(IUpdate.class));
         EasyMock.expectLastCall();
-        replay(floodLightProvider, eventChannel);
+        replay(floodLightProvider);
 
+        odm.init(modContext);
+        odm.startUp(modContext);
         Command cmd = odm.processPacketIn(sw1, pktIn, (Ethernet) pkt1);
         assertEquals(Command.CONTINUE, cmd);
 
-        verify(eventChannel);
+        EasyMock.verify(floodLightProvider);
     }
 
     /**
-     * This test will test return Command.STOP path in processPacketIn method
-     * by injecting a broadcast packet.
+     * Test ProcessPacket function.
+     * @throws FloodlightModuleException
+     */
+    @Test
+    public void testProcessPacketInHasLink() throws FloodlightModuleException {
+        floodLightProvider.addOFMessageListener(EasyMock.eq(OFType.PACKET_IN),
+                EasyMock.isA(OnosDeviceManager.class));
+        EasyMock.expectLastCall();
+        replay(floodLightProvider);
+
+        odm.init(modContext);
+        odm.startUp(modContext);
+        Command cmd = odm.processPacketIn(sw1, pktIn2, (Ethernet) pkt1);
+        assertEquals(Command.CONTINUE, cmd);
+
+        EasyMock.verify(floodLightProvider);
+    }
+
+    /**
+     * Test return Command.STOP path in processPacketIn method by injecting a broadcast packet.
      */
     @Test
     public void testProcessPacketInStop() {
@@ -296,99 +311,69 @@
     }
 
     /**
-     * This tests same packet received case.
-     */
-    @Test
-    public void testProcessPacketInSamePacket() {
-        Ethernet eth = (Ethernet) pkt2;
-        OnosDevice srcDevice = odm.getSourceDeviceFromPacket(eth, sw1Dpid, sw1DevPort);
-        odm.entryAdded(srcDevice);
-        srcDevice.setLastSeenTimestamp(lastSeenTimestamp);
-
-        Command cmd = odm.processPacketIn(sw1, pktIn, (Ethernet) pkt2);
-        assertEquals(Command.CONTINUE, cmd);
-        assertTrue(lastSeenTimestamp.before(srcDevice.getLastSeenTimestamp()));
-    }
-
-    /**
-     * This tests the packet with the same MAC but the second one without IP address.
-     */
-    @Test
-    public void testProcessPacketInNoIpAddress() {
-        Ethernet eth = (Ethernet) pkt3;
-        OnosDevice srcDevice = odm.getSourceDeviceFromPacket(eth, sw1Dpid, sw1DevPort);
-        odm.entryAdded(srcDevice);
-        srcDevice.setLastSeenTimestamp(lastSeenTimestamp);
-
-        Command cmd = odm.processPacketIn(sw1, pktIn, (Ethernet) pkt2);
-        assertEquals(Command.CONTINUE, cmd);
-        assertTrue(lastSeenTimestamp.before(srcDevice.getLastSeenTimestamp()));
-    }
-
-    /**
      * Test add a device from the information from packet.
+     * @throws FloodlightModuleException
      */
     @Test
-    public void testAddOnosDevice() {
+    public void testAddOnosDevice() throws FloodlightModuleException {
         Ethernet eth = (Ethernet) pkt1;
         Long longmac = eth.getSourceMAC().toLong();
         OnosDevice srcDevice = odm.getSourceDeviceFromPacket(eth, sw1Dpid, sw1DevPort);
 
         floodLightProvider.addOFMessageListener(EasyMock.eq(OFType.PACKET_IN), EasyMock.isA(OnosDeviceManager.class));
         EasyMock.expectLastCall();
-        eventChannel.addEntry(longmac, srcDevice);
-        EasyMock.expectLastCall();
         floodLightProvider.publishUpdate(EasyMock.isA(IUpdate.class));
         EasyMock.expectLastCall();
-        replay(floodLightProvider, eventChannel);
+        replay(floodLightProvider);
 
+        odm.init(modContext);
+        odm.startUp(modContext);
         odm.addOnosDevice(longmac, srcDevice);
 
-        verify(eventChannel);
+        EasyMock.verify(floodLightProvider);
     }
 
     /**
      * Test delete a device.
+     * @throws FloodlightModuleException
      */
     @Test
-    public void testDeleteOnosDevice() {
+    public void testDeleteOnosDevice() throws FloodlightModuleException {
         Ethernet eth = (Ethernet) pkt1;
-        Long longmac = eth.getSourceMAC().toLong();
         OnosDevice srcDevice = odm.getSourceDeviceFromPacket(eth, sw1Dpid, sw1DevPort);
 
         floodLightProvider.addOFMessageListener(EasyMock.eq(OFType.PACKET_IN), EasyMock.isA(OnosDeviceManager.class));
         EasyMock.expectLastCall();
-        eventChannel.removeEntry(longmac);
-        EasyMock.expectLastCall();
         floodLightProvider.publishUpdate(EasyMock.isA(IUpdate.class));
         EasyMock.expectLastCall();
-        replay(floodLightProvider, eventChannel);
+        replay(floodLightProvider);
 
+        odm.init(modContext);
+        odm.startUp(modContext);
         odm.deleteOnosDevice(srcDevice);
 
-        verify(eventChannel);
+        EasyMock.verify(floodLightProvider);
     }
 
     /**
      * Test delete a device by using its source mac address.
+     * @throws FloodlightModuleException
      */
     @Test
-    public void testDeleteOnosDeviceByMac() {
+    public void testDeleteOnosDeviceByMac() throws FloodlightModuleException {
         Ethernet eth = (Ethernet) pkt1;
         MACAddress mac = eth.getSourceMAC();
-        Long longmac = mac.toLong();
-        OnosDevice srcDevice = odm.getSourceDeviceFromPacket(eth, sw1Dpid, sw1DevPort);
 
         floodLightProvider.addOFMessageListener(EasyMock.eq(OFType.PACKET_IN), EasyMock.isA(OnosDeviceManager.class));
         EasyMock.expectLastCall();
-        eventChannel.removeEntry(longmac);
-        EasyMock.expectLastCall();
         floodLightProvider.publishUpdate(EasyMock.isA(IUpdate.class));
         EasyMock.expectLastCall();
-        replay(floodLightProvider, eventChannel);
+        replay(floodLightProvider);
 
-        odm.entryAdded(srcDevice);
+        odm.init(modContext);
+        odm.startUp(modContext);
         odm.deleteOnosDeviceByMac(mac);
-        verify(eventChannel);
+
+        EasyMock.verify(floodLightProvider);
     }
 }
diff --git a/src/test/java/net/onrc/onos/core/devicemanager/OnosDeviceTest.java b/src/test/java/net/onrc/onos/core/devicemanager/OnosDeviceTest.java
new file mode 100644
index 0000000..6c79bf0
--- /dev/null
+++ b/src/test/java/net/onrc/onos/core/devicemanager/OnosDeviceTest.java
@@ -0,0 +1,65 @@
+package net.onrc.onos.core.devicemanager;
+
+import static org.junit.Assert.assertTrue;
+
+import java.util.Date;
+
+import net.floodlightcontroller.util.MACAddress;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+/*
+ * This is the test for OnosDevice.class.
+ */
+public class OnosDeviceTest {
+
+    MACAddress mac1;
+    MACAddress mac2;
+    Long dpid1;
+    Long dpid2;
+    Long portNum1;
+    Long portNum2;
+    Date date1;
+    Date date2;
+
+    @Before
+    public void setUp() throws Exception {
+        mac1 = MACAddress.valueOf("00:00:00:00:00:01");
+        mac2 = MACAddress.valueOf("00:00:00:00:00:01");
+        dpid1 = 1L;
+        dpid2 = 1L;
+        portNum1 = 1L;
+        portNum2 = 1L;
+        date1 = new Date(1L);
+        date2 = new Date(2L);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+    }
+
+    /*
+     * Test for making sure hashCode function works properly.
+     */
+    @Test
+    public void testHashCode() {
+        OnosDevice dev1 = new OnosDevice(mac1, null, dpid1, portNum1, date1);
+        OnosDevice dev2 = new OnosDevice(mac2, null, dpid2, portNum2, date2);
+
+        assertTrue(dev1.hashCode() == dev2.hashCode());
+    }
+
+    /*
+     * Test for making sure equals function works properly.
+     */
+    @Test
+    public void testEqualsObject() {
+        OnosDevice dev1 = new OnosDevice(mac1, null, dpid1, portNum1, date1);
+        OnosDevice dev2 = new OnosDevice(mac2, null, dpid2, portNum2, date2);
+
+        assertTrue(dev1.equals(dev2));
+    }
+
+}
diff --git a/src/test/java/net/onrc/onos/core/intent/ConstrainedBFSTreeTest.java b/src/test/java/net/onrc/onos/core/intent/ConstrainedBFSTreeTest.java
index 4a58b90..9a3aaa2 100644
--- a/src/test/java/net/onrc/onos/core/intent/ConstrainedBFSTreeTest.java
+++ b/src/test/java/net/onrc/onos/core/intent/ConstrainedBFSTreeTest.java
@@ -5,6 +5,7 @@
 import static org.junit.Assert.assertNull;
 import net.onrc.onos.core.intent.IntentOperation.Operator;
 import net.onrc.onos.core.topology.LinkEvent;
+import net.onrc.onos.core.topology.MockTopology;
 
 import org.junit.After;
 import org.junit.Before;
diff --git a/src/test/java/net/onrc/onos/core/intent/MockTopology.java b/src/test/java/net/onrc/onos/core/intent/MockTopology.java
deleted file mode 100644
index ddbdbe7..0000000
--- a/src/test/java/net/onrc/onos/core/intent/MockTopology.java
+++ /dev/null
@@ -1,86 +0,0 @@
-package net.onrc.onos.core.intent;
-
-import net.onrc.onos.core.topology.Link;
-import net.onrc.onos.core.topology.LinkImpl;
-import net.onrc.onos.core.topology.Switch;
-import net.onrc.onos.core.topology.SwitchImpl;
-import net.onrc.onos.core.topology.TopologyImpl;
-
-/**
- * A mock class of Topology.
- * This class should be used only by test codes.
- */
-public class MockTopology extends TopologyImpl {
-    // TODO this class doesn't seem like it should extend TopologyImpl. It
-    // isn't a Topology, it's more of a TopologyBuilder - methods to
-    // create an populate a fake topology that's not based on discovery
-    // data from the driver modules.
-    // We may well need a MockTopology, but that's not what this class is
-    // doing.
-
-    public static final Long LOCAL_PORT = 0xFFFEL;
-    public SwitchImpl sw1, sw2, sw3, sw4;
-
-    public Switch addSwitch(Long switchId) {
-        SwitchImpl sw = new SwitchImpl(this, switchId);
-        this.putSwitch(sw);
-        return sw;
-    }
-
-    public Link[] addBidirectionalLinks(Long srcDpid, Long srcPortNo, Long dstDpid, Long dstPortNo) {
-        Link[] links = new Link[2];
-        links[0] = new LinkImpl(this, getPort(srcDpid, srcPortNo), getPort(dstDpid, dstPortNo));
-        links[1] = new LinkImpl(this, getPort(dstDpid, dstPortNo), getPort(srcDpid, srcPortNo));
-
-        putLink(links[0]);
-        putLink(links[1]);
-
-        return links;
-    }
-
-    /**
-     * create sample topology of 4 switches and 5 bidirectional links.
-     * <pre>
-     * [1] --- [2]
-     *  |    /  |
-     *  |  /    |
-     * [4] --- [3]
-     * </pre>
-     */
-    public void createSampleTopology1() {
-        sw1 = (SwitchImpl) addSwitch(1L);
-        sw1.addPort(LOCAL_PORT);
-        sw2 = (SwitchImpl) addSwitch(2L);
-        sw2.addPort(LOCAL_PORT);
-        sw3 = (SwitchImpl) addSwitch(3L);
-        sw3.addPort(LOCAL_PORT);
-        sw4 = (SwitchImpl) addSwitch(4L);
-        sw4.addPort(LOCAL_PORT);
-
-        sw1.addPort(12L); // sw1 -> sw2
-        sw1.addPort(14L); // sw1 -> sw4
-        sw2.addPort(21L); // sw2 -> sw1
-        sw2.addPort(23L); // sw2 -> sw3
-        sw2.addPort(24L); // sw2 -> sw4
-        sw3.addPort(32L); // sw3 -> sw2
-        sw3.addPort(34L); // sw3 -> sw4
-        sw4.addPort(41L); // sw4 -> sw1
-        sw4.addPort(42L); // sw4 -> sw2
-        sw4.addPort(43L); // sw4 -> sw3
-
-        addBidirectionalLinks(1L, 12L, 2L, 21L);
-        addBidirectionalLinks(2L, 23L, 3L, 32L);
-        addBidirectionalLinks(3L, 34L, 4L, 43L);
-        addBidirectionalLinks(4L, 41L, 1L, 14L);
-        addBidirectionalLinks(2L, 24L, 4L, 42L);
-
-        // set capacity of all links to 1000Mbps
-        for (Link link : getLinks()) {
-            ((LinkImpl) link).setCapacity(1000.0);
-        }
-    }
-
-    public void removeLink(Long srcDpid, Long srcPortNo, Long dstDpid, Long dstPortNo) {
-        removeLink(getLink(srcDpid, srcPortNo, dstDpid, dstPortNo));
-    }
-}
diff --git a/src/test/java/net/onrc/onos/core/intent/runtime/IntentTestMocks.java b/src/test/java/net/onrc/onos/core/intent/runtime/IntentTestMocks.java
index 1a2e1c5..a6dde8b 100644
--- a/src/test/java/net/onrc/onos/core/intent/runtime/IntentTestMocks.java
+++ b/src/test/java/net/onrc/onos/core/intent/runtime/IntentTestMocks.java
@@ -1,19 +1,5 @@
 package net.onrc.onos.core.intent.runtime;
 
-
-import net.floodlightcontroller.core.module.FloodlightModuleContext;
-import net.floodlightcontroller.restserver.IRestApiService;
-import net.onrc.onos.core.datagrid.IDatagridService;
-import net.onrc.onos.core.datagrid.IEventChannel;
-import net.onrc.onos.core.datagrid.IEventChannelListener;
-import net.onrc.onos.core.intent.IntentOperationList;
-import net.onrc.onos.core.intent.MockTopology;
-import net.onrc.onos.core.intent.runtime.web.IntentWebRoutable;
-import net.onrc.onos.core.registry.IControllerRegistryService;
-import net.onrc.onos.core.topology.ITopologyListener;
-import net.onrc.onos.core.topology.ITopologyService;
-import org.powermock.api.easymock.PowerMock;
-
 import static org.easymock.EasyMock.anyObject;
 import static org.easymock.EasyMock.createMock;
 import static org.easymock.EasyMock.eq;
@@ -21,6 +7,19 @@
 import static org.easymock.EasyMock.expectLastCall;
 import static org.easymock.EasyMock.replay;
 import static org.easymock.EasyMock.verify;
+import net.floodlightcontroller.core.module.FloodlightModuleContext;
+import net.floodlightcontroller.restserver.IRestApiService;
+import net.onrc.onos.core.datagrid.IDatagridService;
+import net.onrc.onos.core.datagrid.IEventChannel;
+import net.onrc.onos.core.datagrid.IEventChannelListener;
+import net.onrc.onos.core.intent.IntentOperationList;
+import net.onrc.onos.core.intent.runtime.web.IntentWebRoutable;
+import net.onrc.onos.core.registry.IControllerRegistryService;
+import net.onrc.onos.core.topology.ITopologyListener;
+import net.onrc.onos.core.topology.ITopologyService;
+import net.onrc.onos.core.topology.MockTopology;
+
+import org.powermock.api.easymock.PowerMock;
 
 /**
  * This class contains all of the mocked code required to run a test that uses
diff --git a/src/test/java/net/onrc/onos/core/intent/runtime/PathCalcRuntimeModuleTest.java b/src/test/java/net/onrc/onos/core/intent/runtime/PathCalcRuntimeModuleTest.java
index 9623436..5d4adb8 100644
--- a/src/test/java/net/onrc/onos/core/intent/runtime/PathCalcRuntimeModuleTest.java
+++ b/src/test/java/net/onrc/onos/core/intent/runtime/PathCalcRuntimeModuleTest.java
@@ -17,10 +17,10 @@
 import net.onrc.onos.core.intent.IntentMap;
 import net.onrc.onos.core.intent.IntentOperation.Operator;
 import net.onrc.onos.core.intent.IntentOperationList;
-import net.onrc.onos.core.intent.MockTopology;
 import net.onrc.onos.core.intent.ShortestPathIntent;
 import net.onrc.onos.core.topology.DeviceEvent;
 import net.onrc.onos.core.topology.LinkEvent;
+import net.onrc.onos.core.topology.MockTopology;
 import net.onrc.onos.core.topology.PortEvent;
 import net.onrc.onos.core.topology.SwitchEvent;
 
diff --git a/src/test/java/net/onrc/onos/core/intent/runtime/UseCaseTest.java b/src/test/java/net/onrc/onos/core/intent/runtime/UseCaseTest.java
index d911d2f..76af2ec 100644
--- a/src/test/java/net/onrc/onos/core/intent/runtime/UseCaseTest.java
+++ b/src/test/java/net/onrc/onos/core/intent/runtime/UseCaseTest.java
@@ -24,7 +24,6 @@
 import net.onrc.onos.core.intent.Intent.IntentState;
 import net.onrc.onos.core.intent.IntentOperation.Operator;
 import net.onrc.onos.core.intent.IntentOperationList;
-import net.onrc.onos.core.intent.MockTopology;
 import net.onrc.onos.core.intent.PathIntent;
 import net.onrc.onos.core.intent.PathIntentMap;
 import net.onrc.onos.core.intent.ShortestPathIntent;
@@ -34,6 +33,7 @@
 import net.onrc.onos.core.topology.ITopologyListener;
 import net.onrc.onos.core.topology.ITopologyService;
 import net.onrc.onos.core.topology.LinkEvent;
+import net.onrc.onos.core.topology.MockTopology;
 import net.onrc.onos.core.topology.PortEvent;
 import net.onrc.onos.core.topology.SwitchEvent;
 import net.onrc.onos.core.topology.Topology;
diff --git a/src/test/java/net/onrc/onos/core/topology/MockTopology.java b/src/test/java/net/onrc/onos/core/topology/MockTopology.java
new file mode 100644
index 0000000..888779a
--- /dev/null
+++ b/src/test/java/net/onrc/onos/core/topology/MockTopology.java
@@ -0,0 +1,140 @@
+package net.onrc.onos.core.topology;
+
+import net.floodlightcontroller.util.MACAddress;
+
+/**
+ * A mock class of Topology.
+ * This class should be used only by test codes.
+ */
+public class MockTopology extends TopologyImpl {
+    // TODO this class doesn't seem like it should extend TopologyImpl. It
+    // isn't a Topology, it's more of a TopologyBuilder - methods to
+    // create an populate a fake topology that's not based on discovery
+    // data from the driver modules.
+    // We may well need a MockTopology, but that's not what this class is
+    // doing.
+
+    public static final Long LOCAL_PORT = 0xFFFEL;
+    public SwitchImpl sw1, sw2, sw3, sw4;
+
+    public Switch addSwitch(Long switchId) {
+        SwitchImpl sw = new SwitchImpl(this, switchId);
+        this.putSwitch(sw);
+        return sw;
+    }
+
+    public Link[] addBidirectionalLinks(Long srcDpid, Long srcPortNo, Long dstDpid, Long dstPortNo) {
+        Link[] links = new Link[2];
+        links[0] = new LinkImpl(this, getPort(srcDpid, srcPortNo), getPort(dstDpid, dstPortNo));
+        links[1] = new LinkImpl(this, getPort(dstDpid, dstPortNo), getPort(srcDpid, srcPortNo));
+
+        putLink(links[0]);
+        putLink(links[1]);
+
+        return links;
+    }
+
+    /**
+     * create sample topology of 4 switches and 5 bidirectional links.
+     * <pre>
+     * [1] --- [2]
+     *  |    /  |
+     *  |  /    |
+     * [4] --- [3]
+     * </pre>
+     */
+    public void createSampleTopology1() {
+        sw1 = (SwitchImpl) addSwitch(1L);
+        sw1.addPort(LOCAL_PORT);
+        sw2 = (SwitchImpl) addSwitch(2L);
+        sw2.addPort(LOCAL_PORT);
+        sw3 = (SwitchImpl) addSwitch(3L);
+        sw3.addPort(LOCAL_PORT);
+        sw4 = (SwitchImpl) addSwitch(4L);
+        sw4.addPort(LOCAL_PORT);
+
+        sw1.addPort(12L); // sw1 -> sw2
+        sw1.addPort(14L); // sw1 -> sw4
+        sw2.addPort(21L); // sw2 -> sw1
+        sw2.addPort(23L); // sw2 -> sw3
+        sw2.addPort(24L); // sw2 -> sw4
+        sw3.addPort(32L); // sw3 -> sw2
+        sw3.addPort(34L); // sw3 -> sw4
+        sw4.addPort(41L); // sw4 -> sw1
+        sw4.addPort(42L); // sw4 -> sw2
+        sw4.addPort(43L); // sw4 -> sw3
+
+        addBidirectionalLinks(1L, 12L, 2L, 21L);
+        addBidirectionalLinks(2L, 23L, 3L, 32L);
+        addBidirectionalLinks(3L, 34L, 4L, 43L);
+        addBidirectionalLinks(4L, 41L, 1L, 14L);
+        addBidirectionalLinks(2L, 24L, 4L, 42L);
+
+        // set capacity of all links to 1000Mbps
+        for (Link link : getLinks()) {
+            ((LinkImpl) link).setCapacity(1000.0);
+        }
+    }
+
+    /**
+     * create sample topology of 4 switches and 5 bidirectional links.
+     * <pre>
+     *
+     *
+     * [H1]-[1] --- [2]
+     *       |    /  |
+     *       |  /    |
+     *      [4] --- [3]-[H3]
+     * </pre>
+     */
+    public void createSampleTopology2() {
+        sw1 = (SwitchImpl) addSwitch(1L);
+        sw1.addPort(LOCAL_PORT);
+        sw2 = (SwitchImpl) addSwitch(2L);
+        sw2.addPort(LOCAL_PORT);
+        sw3 = (SwitchImpl) addSwitch(3L);
+        sw3.addPort(LOCAL_PORT);
+        sw4 = (SwitchImpl) addSwitch(4L);
+        sw4.addPort(LOCAL_PORT);
+
+        Port port12 = sw1.addPort(12L); // sw1 -> sw2
+        Port port14 = sw1.addPort(14L); // sw1 -> sw4
+        Port port15 = sw1.addPort(15L); // sw1 -> h1
+        Port port21 = sw2.addPort(21L); // sw2 -> sw1
+        Port port23 = sw2.addPort(23L); // sw2 -> sw3
+        Port port24 = sw2.addPort(24L); // sw2 -> sw4
+        Port port32 = sw3.addPort(32L); // sw3 -> sw2
+        Port port34 = sw3.addPort(34L); // sw3 -> sw4
+        Port port35 = sw3.addPort(35L); // sw3 -> h3
+        Port port41 = sw4.addPort(41L); // sw4 -> sw1
+        Port port42 = sw4.addPort(42L); // sw4 -> sw2
+        Port port43 = sw4.addPort(43L); // sw4 -> sw3
+
+        MACAddress mac1 = MACAddress.valueOf("00:44:33:22:11:00");
+        DeviceImpl dev1 = new DeviceImpl(this, mac1);
+        dev1.addAttachmentPoint(port15);
+        dev1.setLastSeenTime(1L);
+        this.putDevice(dev1);
+
+        MACAddress mac3 = MACAddress.valueOf("00:11:22:33:44:55");
+        DeviceImpl dev3 = new DeviceImpl(this, mac3);
+        dev3.addAttachmentPoint(port35);
+        dev3.setLastSeenTime(1L);
+        this.putDevice(dev3);
+
+        addBidirectionalLinks(1L, 12L, 2L, 21L);
+        addBidirectionalLinks(2L, 23L, 3L, 32L);
+        addBidirectionalLinks(3L, 34L, 4L, 43L);
+        addBidirectionalLinks(4L, 41L, 1L, 14L);
+        addBidirectionalLinks(2L, 24L, 4L, 42L);
+
+        // set capacity of all links to 1000Mbps
+        for (Link link : getLinks()) {
+            ((LinkImpl) link).setCapacity(1000.0);
+        }
+    }
+
+    public void removeLink(Long srcDpid, Long srcPortNo, Long dstDpid, Long dstPortNo) {
+        removeLink(getLink(srcDpid, srcPortNo, dstDpid, dstPortNo));
+    }
+}