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 a99fc10..8d5a6d6 100644
--- a/src/test/java/net/onrc/onos/core/intent/ConstrainedBFSTreeTest.java
+++ b/src/test/java/net/onrc/onos/core/intent/ConstrainedBFSTreeTest.java
@@ -26,81 +26,81 @@
 
     @Test
     public void testCreate() {
-        MockNetworkGraph graph = new MockNetworkGraph();
-        graph.createSampleTopology1();
-        ConstrainedBFSTree tree = new ConstrainedBFSTree(graph.getSwitch(1L));
+        MockTopology topology = new MockTopology();
+        topology.createSampleTopology1();
+        ConstrainedBFSTree tree = new ConstrainedBFSTree(topology.getSwitch(1L));
         assertNotNull(tree);
     }
 
     @Test
     public void testCreateConstrained() {
-        MockNetworkGraph graph = new MockNetworkGraph();
-        graph.createSampleTopology1();
+        MockTopology topology = new MockTopology();
+        topology.createSampleTopology1();
         PathIntentMap intents = new PathIntentMap();
-        ConstrainedBFSTree tree = new ConstrainedBFSTree(graph.getSwitch(1L), intents, 1000.0);
+        ConstrainedBFSTree tree = new ConstrainedBFSTree(topology.getSwitch(1L), intents, 1000.0);
         assertNotNull(tree);
     }
 
     @Test
     public void testGetPath() {
-        MockNetworkGraph graph = new MockNetworkGraph();
-        graph.createSampleTopology1();
-        ConstrainedBFSTree tree = new ConstrainedBFSTree(graph.getSwitch(1L));
-        Path path11 = tree.getPath(graph.getSwitch(1L));
-        Path path12 = tree.getPath(graph.getSwitch(2L));
-        Path path13 = tree.getPath(graph.getSwitch(3L));
-        Path path14 = tree.getPath(graph.getSwitch(4L));
+        MockTopology topology = new MockTopology();
+        topology.createSampleTopology1();
+        ConstrainedBFSTree tree = new ConstrainedBFSTree(topology.getSwitch(1L));
+        Path path11 = tree.getPath(topology.getSwitch(1L));
+        Path path12 = tree.getPath(topology.getSwitch(2L));
+        Path path13 = tree.getPath(topology.getSwitch(3L));
+        Path path14 = tree.getPath(topology.getSwitch(4L));
 
         assertNotNull(path11);
         assertEquals(0, path11.size());
 
         assertNotNull(path12);
         assertEquals(1, path12.size());
-        assertEquals(new LinkEvent(graph.getOutgoingLink(1L, 12L)), path12.get(0));
+        assertEquals(new LinkEvent(topology.getOutgoingLink(1L, 12L)), path12.get(0));
 
         assertNotNull(path13);
         assertEquals(2, path13.size());
         if (path13.get(0).getDst().getDpid() == 2L) {
-            assertEquals(new LinkEvent(graph.getOutgoingLink(1L, 12L)), path13.get(0));
-            assertEquals(new LinkEvent(graph.getOutgoingLink(2L, 23L)), path13.get(1));
+            assertEquals(new LinkEvent(topology.getOutgoingLink(1L, 12L)), path13.get(0));
+            assertEquals(new LinkEvent(topology.getOutgoingLink(2L, 23L)), path13.get(1));
         } else {
-            assertEquals(new LinkEvent(graph.getOutgoingLink(1L, 14L)), path13.get(0));
-            assertEquals(new LinkEvent(graph.getOutgoingLink(4L, 43L)), path13.get(1));
+            assertEquals(new LinkEvent(topology.getOutgoingLink(1L, 14L)), path13.get(0));
+            assertEquals(new LinkEvent(topology.getOutgoingLink(4L, 43L)), path13.get(1));
         }
 
         assertNotNull(path14);
         assertEquals(1, path14.size());
-        assertEquals(new LinkEvent(graph.getOutgoingLink(1L, 14L)), path14.get(0));
+        assertEquals(new LinkEvent(topology.getOutgoingLink(1L, 14L)), path14.get(0));
     }
 
     @Test
     public void testGetPathNull() {
-        MockNetworkGraph graph = new MockNetworkGraph();
-        graph.createSampleTopology1();
-        graph.removeLink(1L, 12L, 2L, 21L);
-        graph.removeLink(1L, 14L, 4L, 41L);
+        MockTopology topology = new MockTopology();
+        topology.createSampleTopology1();
+        topology.removeLink(1L, 12L, 2L, 21L);
+        topology.removeLink(1L, 14L, 4L, 41L);
         // now, there is no path from switch 1, but to switch1
 
-        ConstrainedBFSTree tree1 = new ConstrainedBFSTree(graph.getSwitch(1L));
-        Path path12 = tree1.getPath(graph.getSwitch(2L));
-        Path path13 = tree1.getPath(graph.getSwitch(3L));
-        Path path14 = tree1.getPath(graph.getSwitch(4L));
+        ConstrainedBFSTree tree1 = new ConstrainedBFSTree(topology.getSwitch(1L));
+        Path path12 = tree1.getPath(topology.getSwitch(2L));
+        Path path13 = tree1.getPath(topology.getSwitch(3L));
+        Path path14 = tree1.getPath(topology.getSwitch(4L));
 
-        ConstrainedBFSTree tree2 = new ConstrainedBFSTree(graph.getSwitch(2L));
-        Path path21 = tree2.getPath(graph.getSwitch(1L));
+        ConstrainedBFSTree tree2 = new ConstrainedBFSTree(topology.getSwitch(2L));
+        Path path21 = tree2.getPath(topology.getSwitch(1L));
 
         assertNull(path12);
         assertNull(path13);
         assertNull(path14);
         assertNotNull(path21);
         assertEquals(1, path21.size());
-        assertEquals(new LinkEvent(graph.getOutgoingLink(2L, 21L)), path21.get(0));
+        assertEquals(new LinkEvent(topology.getOutgoingLink(2L, 21L)), path21.get(0));
     }
 
     @Test
     public void testGetConstrainedPath() {
-        MockNetworkGraph graph = new MockNetworkGraph();
-        graph.createSampleTopology1();
+        MockTopology topology = new MockTopology();
+        topology.createSampleTopology1();
         PathIntentMap intents = new PathIntentMap();
         IntentOperationList intentOps = new IntentOperationList();
 
@@ -111,33 +111,33 @@
                 "2", 1L, LOCAL_PORT, 0x333L, 2L, LOCAL_PORT, 0x444L, 600.0);
 
         // calculate path of the intent1
-        ConstrainedBFSTree tree = new ConstrainedBFSTree(graph.getSwitch(1L), intents, 600.0);
-        Path path1 = tree.getPath(graph.getSwitch(2L));
+        ConstrainedBFSTree tree = new ConstrainedBFSTree(topology.getSwitch(1L), intents, 600.0);
+        Path path1 = tree.getPath(topology.getSwitch(2L));
 
         assertNotNull(path1);
         assertEquals(1, path1.size());
-        assertEquals(new LinkEvent(graph.getOutgoingLink(1L, 12L)), path1.get(0));
+        assertEquals(new LinkEvent(topology.getOutgoingLink(1L, 12L)), path1.get(0));
 
         PathIntent pathIntent1 = new PathIntent("pi1", path1, 600.0, intent1);
         intentOps.add(Operator.ADD, pathIntent1);
         intents.executeOperations(intentOps);
 
         // calculate path of the intent2
-        tree = new ConstrainedBFSTree(graph.getSwitch(1L), intents, 600.0);
-        Path path2 = tree.getPath(graph.getSwitch(2L));
+        tree = new ConstrainedBFSTree(topology.getSwitch(1L), intents, 600.0);
+        Path path2 = tree.getPath(topology.getSwitch(2L));
 
         assertNotNull(path2);
         assertEquals(2, path2.size());
-        assertEquals(new LinkEvent(graph.getOutgoingLink(1L, 14L)), path2.get(0));
-        assertEquals(new LinkEvent(graph.getOutgoingLink(4L, 42L)), path2.get(1));
+        assertEquals(new LinkEvent(topology.getOutgoingLink(1L, 14L)), path2.get(0));
+        assertEquals(new LinkEvent(topology.getOutgoingLink(4L, 42L)), path2.get(1));
 
         PathIntent pathIntent2 = new PathIntent("pi2", path2, 600.0, intent2);
         intentOps.add(Operator.ADD, pathIntent2);
         intents.executeOperations(intentOps);
 
         // calculate path of the intent3
-        tree = new ConstrainedBFSTree(graph.getSwitch(1L), intents, 600.0);
-        Path path3 = tree.getPath(graph.getSwitch(2L));
+        tree = new ConstrainedBFSTree(topology.getSwitch(1L), intents, 600.0);
+        Path path3 = tree.getPath(topology.getSwitch(2L));
 
         assertNull(path3);
     }
diff --git a/src/test/java/net/onrc/onos/core/intent/MockNetworkGraph.java b/src/test/java/net/onrc/onos/core/intent/MockTopology.java
similarity index 84%
rename from src/test/java/net/onrc/onos/core/intent/MockNetworkGraph.java
rename to src/test/java/net/onrc/onos/core/intent/MockTopology.java
index d481182..680acc2 100644
--- a/src/test/java/net/onrc/onos/core/intent/MockNetworkGraph.java
+++ b/src/test/java/net/onrc/onos/core/intent/MockTopology.java
@@ -2,22 +2,22 @@
 
 import net.onrc.onos.core.topology.Link;
 import net.onrc.onos.core.topology.LinkImpl;
-import net.onrc.onos.core.topology.NetworkGraphImpl;
 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 NetworkGraph.
+ * A mock class of Topology.
  * This class should be used only by test codes.
  *
  * @author Toshio Koide (t-koide@onlab.us)
  */
-public class MockNetworkGraph extends NetworkGraphImpl {
-    // TODO this class doesn't seem like it should extend NetworkGraphImpl. It
-    // isn't a NetworkGraph, it's more of a NetworkGraphBuilder - methods to
-    // create an populate a fake network graph that's not based on discovery
+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 MockNetworkGraph, but that's not what this class is
+    // We may well need a MockTopology, but that's not what this class is
     // doing.
 
     public static Long LOCAL_PORT = 0xFFFEL;
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 5e1a11d..2d57cfe 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
@@ -20,7 +20,6 @@
 import net.floodlightcontroller.core.module.FloodlightModuleContext;
 import net.floodlightcontroller.core.module.FloodlightModuleException;
 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;
@@ -29,13 +28,13 @@
 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.MockNetworkGraph;
+import net.onrc.onos.core.intent.MockTopology;
 import net.onrc.onos.core.intent.ShortestPathIntent;
 import net.onrc.onos.core.intent.runtime.web.IntentWebRoutable;
 import net.onrc.onos.core.registry.IControllerRegistryService;
 import net.onrc.onos.core.topology.DeviceEvent;
-import net.onrc.onos.core.topology.INetworkGraphListener;
-import net.onrc.onos.core.topology.INetworkGraphService;
+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.PortEvent;
 import net.onrc.onos.core.topology.SwitchEvent;
@@ -58,7 +57,7 @@
  *         <p/>
  *         Unit tests for the Path Calculation Runtime module (PathCalcRuntimeModule).
  *         These test cases check the results of creating paths, deleting paths, and
- *         rerouting paths.  The network graph, controller registry, and data grid are
+ *         rerouting paths.  The topology, controller registry, and data grid are
  *         mocked out.  The individual tests check the high level intents and the
  *         resulting operation lists to be sure they match the intended APIs.
  */
@@ -69,22 +68,22 @@
 
     private FloodlightModuleContext modContext;
     private IDatagridService datagridService;
-    private INetworkGraphService networkGraphService;
+    private ITopologyService topologyService;
     private IControllerRegistryService controllerRegistryService;
     private PersistIntent persistIntent;
     private IRestApiService restApi;
-    private MockNetworkGraph graph;
+    private MockTopology topology;
     private IEventChannel<Long, IntentOperationList> intentOperationChannel;
     private IEventChannel<Long, IntentStateList> intentStateChannel;
 
     @SuppressWarnings("unchecked")
     @Before
     public void setUp() throws Exception {
-        graph = new MockNetworkGraph();
-        graph.createSampleTopology1();
+        topology = new MockTopology();
+        topology.createSampleTopology1();
 
         datagridService = createMock(IDatagridService.class);
-        networkGraphService = createMock(INetworkGraphService.class);
+        topologyService = createMock(ITopologyService.class);
         controllerRegistryService = createMock(IControllerRegistryService.class);
         modContext = createMock(FloodlightModuleContext.class);
         intentOperationChannel = createMock(IEventChannel.class);
@@ -97,8 +96,8 @@
 
         expect(modContext.getServiceImpl(IDatagridService.class))
                 .andReturn(datagridService).once();
-        expect(modContext.getServiceImpl(INetworkGraphService.class))
-                .andReturn(networkGraphService).once();
+        expect(modContext.getServiceImpl(ITopologyService.class))
+                .andReturn(topologyService).once();
         expect(modContext.getServiceImpl(IControllerRegistryService.class))
                 .andReturn(controllerRegistryService).once();
         expect(persistIntent.getKey()).andReturn(1L).anyTimes();
@@ -108,10 +107,10 @@
         expect(modContext.getServiceImpl(IRestApiService.class))
                 .andReturn(restApi).once();
 
-        expect(networkGraphService.getNetworkGraph()).andReturn(graph)
+        expect(topologyService.getTopology()).andReturn(topology)
                 .anyTimes();
-        networkGraphService.registerNetworkGraphListener(
-                anyObject(INetworkGraphListener.class));
+        topologyService.registerTopologyListener(
+                anyObject(ITopologyListener.class));
         expectLastCall();
 
         expect(datagridService.createChannel("onos.pathintent",
@@ -127,7 +126,7 @@
         restApi.addRestletRoutable(anyObject(IntentWebRoutable.class));
 
         replay(datagridService);
-        replay(networkGraphService);
+        replay(topologyService);
         replay(modContext);
         replay(controllerRegistryService);
         PowerMock.replay(persistIntent, PersistIntent.class);
@@ -240,7 +239,7 @@
     @After
     public void tearDown() {
         verify(datagridService);
-        verify(networkGraphService);
+        verify(topologyService);
         verify(modContext);
         verify(controllerRegistryService);
         PowerMock.verify(persistIntent, PersistIntent.class);
@@ -494,13 +493,13 @@
         final List<LinkEvent> addedLinkEvents = new LinkedList<>();
         final List<LinkEvent> removedLinkEvents = new LinkedList<>();
 
-        graph.removeLink(1L, 12L, 2L, 21L); // This link is used by the intent "1"
-        graph.removeLink(2L, 21L, 1L, 12L);
+        topology.removeLink(1L, 12L, 2L, 21L); // This link is used by the intent "1"
+        topology.removeLink(2L, 21L, 1L, 12L);
         LinkEvent linkEvent1 = new LinkEvent(1L, 12L, 2L, 21L);
         LinkEvent linkEvent2 = new LinkEvent(2L, 21L, 1L, 12L);
         removedLinkEvents.add(linkEvent1);
         removedLinkEvents.add(linkEvent2);
-        runtime.networkGraphEvents(
+        runtime.topologyEvents(
                 emptySwitchEvents,
                 emptySwitchEvents,
                 emptyPortEvents,
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 f3c9aaa..8cacabc 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
@@ -25,19 +25,19 @@
 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.MockNetworkGraph;
+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;
 import net.onrc.onos.core.intent.runtime.web.IntentWebRoutable;
 import net.onrc.onos.core.registry.IControllerRegistryService;
 import net.onrc.onos.core.topology.DeviceEvent;
-import net.onrc.onos.core.topology.INetworkGraphListener;
-import net.onrc.onos.core.topology.INetworkGraphService;
+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.NetworkGraph;
 import net.onrc.onos.core.topology.PortEvent;
 import net.onrc.onos.core.topology.SwitchEvent;
+import net.onrc.onos.core.topology.Topology;
 
 import org.junit.After;
 import org.junit.Before;
@@ -57,10 +57,10 @@
 @RunWith(PowerMockRunner.class)
 @PrepareForTest(PathCalcRuntimeModule.class)
 public class UseCaseTest {
-    private NetworkGraph g;
+    private Topology topology;
     private FloodlightModuleContext modContext;
     private IDatagridService datagridService;
-    private INetworkGraphService networkGraphService;
+    private ITopologyService topologyService;
     private IControllerRegistryService controllerRegistryService;
     private PersistIntent persistIntent;
     private IRestApiService restApi;
@@ -72,12 +72,12 @@
     @SuppressWarnings("unchecked")
     @Before
     public void setUp() throws Exception {
-        MockNetworkGraph graph = new MockNetworkGraph();
-        graph.createSampleTopology1();
-        g = graph;
+        MockTopology topology = new MockTopology();
+        topology.createSampleTopology1();
+        this.topology = topology;
 
         datagridService = createMock(IDatagridService.class);
-        networkGraphService = createMock(INetworkGraphService.class);
+        topologyService = createMock(ITopologyService.class);
         controllerRegistryService = createMock(IControllerRegistryService.class);
         modContext = createMock(FloodlightModuleContext.class);
         intentOperationChannel = createMock(IEventChannel.class);
@@ -90,8 +90,8 @@
 
         expect(modContext.getServiceImpl(IDatagridService.class))
                 .andReturn(datagridService).once();
-        expect(modContext.getServiceImpl(INetworkGraphService.class))
-                .andReturn(networkGraphService).once();
+        expect(modContext.getServiceImpl(ITopologyService.class))
+                .andReturn(topologyService).once();
         expect(modContext.getServiceImpl(IControllerRegistryService.class))
                 .andReturn(controllerRegistryService).once();
         expect(persistIntent.getKey()).andReturn(1L).anyTimes();
@@ -100,8 +100,8 @@
         expect(modContext.getServiceImpl(IRestApiService.class))
                 .andReturn(restApi).once();
 
-        expect(networkGraphService.getNetworkGraph()).andReturn(g).anyTimes();
-        networkGraphService.registerNetworkGraphListener(anyObject(INetworkGraphListener.class));
+        expect(topologyService.getTopology()).andReturn(topology).anyTimes();
+        topologyService.registerTopologyListener(anyObject(ITopologyListener.class));
         expectLastCall();
 
         expect(datagridService.createChannel("onos.pathintent", Long.class, IntentOperationList.class))
@@ -116,7 +116,7 @@
         restApi.addRestletRoutable(anyObject(IntentWebRoutable.class));
 
         replay(datagridService);
-        replay(networkGraphService);
+        replay(topologyService);
         replay(modContext);
         replay(controllerRegistryService);
         PowerMock.replay(persistIntent, PersistIntent.class);
@@ -126,7 +126,7 @@
     @After
     public void tearDown() {
         verify(datagridService);
-        verify(networkGraphService);
+        verify(topologyService);
         verify(modContext);
         verify(controllerRegistryService);
         PowerMock.verify(persistIntent, PersistIntent.class);
@@ -258,14 +258,14 @@
         runtime1.getPathIntents().changeStates(states);
 
         // link down
-        ((MockNetworkGraph) g).removeLink(1L, 12L, 2L, 21L); // This link is used by the intent "1"
-        ((MockNetworkGraph) g).removeLink(2L, 21L, 1L, 12L);
+        ((MockTopology) topology).removeLink(1L, 12L, 2L, 21L); // This link is used by the intent "1"
+        ((MockTopology) topology).removeLink(2L, 21L, 1L, 12L);
         LinkEvent linkEvent1 = new LinkEvent(1L, 12L, 2L, 21L);
         LinkEvent linkEvent2 = new LinkEvent(2L, 21L, 1L, 12L);
         removedLinkEvents.clear();
         removedLinkEvents.add(linkEvent1);
         removedLinkEvents.add(linkEvent2);
-        runtime1.networkGraphEvents(
+        runtime1.topologyEvents(
                 addedSwitchEvents,
                 removedSwitchEvents,
                 addedPortEvents,