diff --git a/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkDeviceServiceTest.java b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkDeviceServiceTest.java
new file mode 100644
index 0000000..26e5080
--- /dev/null
+++ b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkDeviceServiceTest.java
@@ -0,0 +1,352 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.virtual.impl;
+
+import com.google.common.collect.Iterators;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.junit.TestUtils;
+import org.onosproject.common.event.impl.TestEventDispatcher;
+import org.onosproject.core.CoreService;
+import org.onosproject.core.CoreServiceAdapter;
+import org.onosproject.core.IdGenerator;
+import org.onosproject.incubator.net.virtual.TenantId;
+import org.onosproject.incubator.net.virtual.VirtualDevice;
+import org.onosproject.incubator.net.virtual.VirtualNetwork;
+import org.onosproject.incubator.net.virtual.VirtualPort;
+import org.onosproject.incubator.store.virtual.impl.DistributedVirtualNetworkStore;
+import org.onosproject.net.DefaultPort;
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.MastershipRole;
+import org.onosproject.net.NetTestTools;
+import org.onosproject.net.Port;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.store.service.TestStorageService;
+
+import java.util.Iterator;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.junit.Assert.*;
+
+/**
+ * Junit tests for VirtualNetworkDeviceService.
+ */
+public class VirtualNetworkDeviceServiceTest {
+    private final String tenantIdValue1 = "TENANT_ID1";
+    private final String deviceIdValue1 = "DEVICE_ID1";
+    private final String deviceIdValue2 = "DEVICE_ID2";
+    private final String deviceIdValue3 = "DEVICE_ID3";
+
+    private VirtualNetworkManager manager;
+    private DistributedVirtualNetworkStore virtualNetworkManagerStore;
+    private CoreService coreService;
+
+    @Before
+    public void setUp() throws Exception {
+        virtualNetworkManagerStore = new DistributedVirtualNetworkStore();
+
+        coreService = new VirtualNetworkDeviceServiceTest.TestCoreService();
+        virtualNetworkManagerStore.setCoreService(coreService);
+        TestUtils.setField(coreService, "coreService", new VirtualNetworkDeviceServiceTest.TestCoreService());
+        TestUtils.setField(virtualNetworkManagerStore, "storageService", new TestStorageService());
+        virtualNetworkManagerStore.activate();
+
+        manager = new VirtualNetworkManager();
+        manager.store = virtualNetworkManagerStore;
+        NetTestTools.injectEventDispatcher(manager, new TestEventDispatcher());
+        manager.activate();
+    }
+
+    @After
+    public void tearDown() {
+        virtualNetworkManagerStore.deactivate();
+        manager.deactivate();
+        NetTestTools.injectEventDispatcher(manager, null);
+    }
+
+    /**
+     * Tests the getDevices(), getAvailableDevices(), getDeviceCount(), getDevice(), and isAvailable() methods.
+     */
+    @Test
+    public void testGetDevices() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        VirtualDevice device1 = manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue1));
+        VirtualDevice device2 = manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getDevices() method
+        Iterator<Device> it = deviceService.getDevices().iterator();
+        assertEquals("The device set size did not match.", 2, Iterators.size(it));
+
+        // test the getAvailableDevices() method
+        Iterator<Device> it2 = deviceService.getAvailableDevices().iterator();
+        assertEquals("The device set size did not match.", 2, Iterators.size(it2));
+
+        // test the getDeviceCount() method
+        assertEquals("The device set size did not match.", 2, deviceService.getDeviceCount());
+
+        // test the getDevice() method
+        assertEquals("The expect device did not match.", device1,
+                     deviceService.getDevice(DeviceId.deviceId(deviceIdValue1)));
+        assertNotEquals("The expect device should not have matched.", device1,
+                        deviceService.getDevice(DeviceId.deviceId(deviceIdValue2)));
+
+        // test the isAvailable() method
+        assertTrue("The expect device availability did not match.",
+                   deviceService.isAvailable(DeviceId.deviceId(deviceIdValue1)));
+        assertFalse("The expect device availability did not match.",
+                    deviceService.isAvailable(DeviceId.deviceId(deviceIdValue3)));
+    }
+
+    /**
+     * Tests querying for a device using a null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetDeviceByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getDevice() method with null device id value.
+        deviceService.getDevice(null);
+    }
+
+    /**
+     * Tests querying for a device using a null device type.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetDeviceByNullType() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getDevices() method with null type value.
+        deviceService.getDevices(null);
+    }
+
+    /**
+     * Tests the isAvailable method using a null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testIsAvailableByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the isAvailable() method with null device id value.
+        deviceService.isAvailable(null);
+    }
+
+    /**
+     * Tests querying for a device and available devices by device type.
+     */
+    @Test
+    public void testGetDeviceType() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue1));
+        manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getDevices(Type) method.
+        Iterator<Device> it = deviceService.getDevices(Device.Type.VIRTUAL).iterator();
+        assertEquals("The device set size did not match.", 2, Iterators.size(it));
+        Iterator<Device> it2 = deviceService.getDevices(Device.Type.SWITCH).iterator();
+        assertEquals("The device set size did not match.", 0, Iterators.size(it2));
+
+        // test the getAvailableDevices(Type) method.
+        Iterator<Device> it3 = deviceService.getAvailableDevices(Device.Type.VIRTUAL).iterator();
+        assertEquals("The device set size did not match.", 2, Iterators.size(it3));
+    }
+
+    /**
+     * Tests querying the role of a device by null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetRoleByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getRole() method using a null device identifier
+        deviceService.getRole(null);
+    }
+
+    /**
+     * Tests querying the role of a device by device identifier.
+     */
+    @Test
+    public void testGetRole() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getRole() method
+        assertEquals("The expect device role did not match.", MastershipRole.MASTER,
+                     deviceService.getRole(DeviceId.deviceId(deviceIdValue1)));
+    }
+
+    /**
+     * Tests querying the ports of a device by null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetPortsByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getPorts() method using a null device identifier
+        deviceService.getPorts(null);
+    }
+
+    /**
+     * Tests querying the ports of a device by device identifier.
+     */
+    @Test
+    public void testGetPorts() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        VirtualDevice virtualDevice = manager.createVirtualDevice(virtualNetwork.id(),
+                                                                  DeviceId.deviceId(deviceIdValue1));
+        manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        Port port = new DefaultPort(virtualDevice, PortNumber.portNumber(1), true);
+
+        manager.createVirtualPort(virtualNetwork.id(), virtualDevice.id(), PortNumber.portNumber(1), port);
+        manager.createVirtualPort(virtualNetwork.id(), virtualDevice.id(), PortNumber.portNumber(2), port);
+
+        // test the getPorts() method
+        assertEquals("The port set size did not match.", 2,
+                     deviceService.getPorts(DeviceId.deviceId(deviceIdValue1)).size());
+        assertEquals("The port set size did not match.", 0,
+                     deviceService.getPorts(DeviceId.deviceId(deviceIdValue2)).size());
+    }
+
+    /**
+     * Tests querying the port of a device by device identifier and port number.
+     */
+    @Test
+    public void testGetPort() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        VirtualDevice virtualDevice = manager.createVirtualDevice(virtualNetwork.id(),
+                                                                  DeviceId.deviceId(deviceIdValue1));
+        manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        Port port = new DefaultPort(virtualDevice, PortNumber.portNumber(1), true);
+
+        VirtualPort virtualPort1 = manager.createVirtualPort(virtualNetwork.id(), virtualDevice.id(),
+                                                             PortNumber.portNumber(1), port);
+        manager.createVirtualPort(virtualNetwork.id(), virtualDevice.id(), PortNumber.portNumber(2), port);
+
+        // test the getPort() method
+        assertEquals("The port did not match as expected.", virtualPort1,
+                     deviceService.getPort(DeviceId.deviceId(deviceIdValue1), PortNumber.portNumber(1)));
+        assertNotEquals("The port did not match as expected.", virtualPort1,
+                        deviceService.getPort(DeviceId.deviceId(deviceIdValue1), PortNumber.portNumber(3)));
+    }
+
+    /**
+     * Tests querying the port statistics of a device by null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetPortsStatisticsByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getPortStatistics() method using a null device identifier
+        deviceService.getPortStatistics(null);
+    }
+
+    /**
+     * Tests querying the port statistics of a device by device identifier.
+     */
+    @Test
+    public void testGetPortStatistics() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        VirtualDevice virtualDevice = manager.createVirtualDevice(virtualNetwork.id(),
+                                                                  DeviceId.deviceId(deviceIdValue1));
+        manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getPortStatistics() method
+        assertEquals("The port statistics set size did not match.", 0,
+                     deviceService.getPortStatistics(DeviceId.deviceId(deviceIdValue1)).size());
+    }
+
+    /**
+     * Tests querying the port delta statistics of a device by null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetPortsDeltaStatisticsByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getPortDeltaStatistics() method using a null device identifier
+        deviceService.getPortDeltaStatistics(null);
+    }
+
+    /**
+     * Tests querying the port delta statistics of a device by device identifier.
+     */
+    @Test
+    public void testGetPortDeltaStatistics() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        VirtualDevice virtualDevice = manager.createVirtualDevice(virtualNetwork.id(),
+                                                                  DeviceId.deviceId(deviceIdValue1));
+        manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+
+        DeviceService deviceService = manager.get(virtualNetwork.id(), DeviceService.class);
+
+        // test the getPortDeltaStatistics() method
+        assertEquals("The port delta statistics set size did not match.", 0,
+                     deviceService.getPortDeltaStatistics(DeviceId.deviceId(deviceIdValue1)).size());
+    }
+
+    /**
+     * Core service test class.
+     */
+    private class TestCoreService extends CoreServiceAdapter {
+
+        @Override
+        public IdGenerator getIdGenerator(String topic) {
+            return new IdGenerator() {
+                private AtomicLong counter = new AtomicLong(0);
+
+                @Override
+                public long getNewId() {
+                    return counter.getAndIncrement();
+                }
+            };
+        }
+    }
+}
diff --git a/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkLinkServiceTest.java b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkLinkServiceTest.java
new file mode 100644
index 0000000..5143b8b
--- /dev/null
+++ b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkLinkServiceTest.java
@@ -0,0 +1,317 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.virtual.impl;
+
+import com.google.common.collect.Iterators;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.junit.TestUtils;
+import org.onosproject.common.event.impl.TestEventDispatcher;
+import org.onosproject.core.CoreService;
+import org.onosproject.core.CoreServiceAdapter;
+import org.onosproject.core.IdGenerator;
+import org.onosproject.incubator.net.virtual.TenantId;
+import org.onosproject.incubator.net.virtual.VirtualDevice;
+import org.onosproject.incubator.net.virtual.VirtualLink;
+import org.onosproject.incubator.net.virtual.VirtualNetwork;
+import org.onosproject.incubator.store.virtual.impl.DistributedVirtualNetworkStore;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.Link;
+import org.onosproject.net.NetTestTools;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.link.LinkService;
+import org.onosproject.store.service.TestStorageService;
+
+import java.util.Iterator;
+import java.util.concurrent.atomic.AtomicLong;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+/**
+ * Junit tests for VirtualNetworkLinkService.
+ */
+public class VirtualNetworkLinkServiceTest {
+
+    private final String tenantIdValue1 = "TENANT_ID1";
+    private final String deviceIdValue1 = "DEVICE_ID1";
+    private final String deviceIdValue2 = "DEVICE_ID2";
+    private final String deviceIdValue3 = "DEVICE_ID3";
+
+    private VirtualNetworkManager manager;
+    private DistributedVirtualNetworkStore virtualNetworkManagerStore;
+    private CoreService coreService;
+
+    @Before
+    public void setUp() throws Exception {
+        virtualNetworkManagerStore = new DistributedVirtualNetworkStore();
+
+        coreService = new VirtualNetworkLinkServiceTest.TestCoreService();
+        virtualNetworkManagerStore.setCoreService(coreService);
+        TestUtils.setField(coreService, "coreService", new VirtualNetworkLinkServiceTest.TestCoreService());
+        TestUtils.setField(virtualNetworkManagerStore, "storageService", new TestStorageService());
+        virtualNetworkManagerStore.activate();
+
+        manager = new VirtualNetworkManager();
+        manager.store = virtualNetworkManagerStore;
+        NetTestTools.injectEventDispatcher(manager, new TestEventDispatcher());
+        manager.activate();
+    }
+
+    @After
+    public void tearDown() {
+        virtualNetworkManagerStore.deactivate();
+        manager.deactivate();
+        NetTestTools.injectEventDispatcher(manager, null);
+    }
+
+    /**
+     * Tests the getLinks(), getActiveLinks(), getLinkCount(), getLink(),
+     * getLinks(ConnectPoint), getDeviceLinks(), getDeviceEgressLinks(), getDeviceIngressLinks(),
+     * getEgressLinks(), getIngressLinks() methods.
+     */
+    @Test
+    public void testGetLinks() {
+
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        VirtualDevice srcVirtualDevice =
+                manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue1));
+        VirtualDevice dstVirtualDevice =
+                manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+        ConnectPoint src = new ConnectPoint(srcVirtualDevice.id(), PortNumber.portNumber(1));
+        ConnectPoint dst = new ConnectPoint(dstVirtualDevice.id(), PortNumber.portNumber(2));
+        VirtualLink link1 = manager.createVirtualLink(virtualNetwork.id(), src, dst);
+        VirtualLink link2 = manager.createVirtualLink(virtualNetwork.id(), dst, src);
+
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getLinks() method
+        Iterator<Link> it = linkService.getLinks().iterator();
+        assertEquals("The link set size did not match.", 2, Iterators.size(it));
+
+        // test the getActiveLinks() method where no links are ACTIVE
+        Iterator<Link> it2 = linkService.getActiveLinks().iterator();
+        assertEquals("The link set size did not match.", 0, Iterators.size(it2));
+
+        // test the getActiveLinks() method where one link is ACTIVE
+        virtualNetworkManagerStore.updateLink(link1, link1.tunnelId(), Link.State.ACTIVE);
+        Iterator<Link> it3 = linkService.getActiveLinks().iterator();
+        assertEquals("The link set size did not match.", 1, Iterators.size(it3));
+
+        // test the getLinkCount() method
+        assertEquals("The link set size did not match.", 2, linkService.getLinkCount());
+
+        // test the getLink() method
+        assertEquals("The expect link did not match.", link1,
+                     linkService.getLink(src, dst));
+        assertEquals("The expect link did not match.", link2,
+                     linkService.getLink(dst, src));
+        assertNotEquals("The expect link should not have matched.", link1,
+                        linkService.getLink(dst, src));
+
+        // test the getLinks(ConnectPoint) method
+        assertEquals("The link set size did not match.", 2, linkService.getLinks(src).size());
+        assertEquals("The link set size did not match.", 2, linkService.getLinks(dst).size());
+        ConnectPoint connectPoint = new ConnectPoint(dstVirtualDevice.id(), PortNumber.portNumber(3));
+        assertEquals("The link set size did not match.", 0, linkService.getLinks(connectPoint).size());
+
+        // test the getDeviceLinks() method
+        assertEquals("The link set size did not match.", 2,
+                     linkService.getDeviceLinks(DeviceId.deviceId(deviceIdValue1)).size());
+        assertEquals("The link set size did not match.", 2,
+                     linkService.getDeviceLinks(DeviceId.deviceId(deviceIdValue2)).size());
+        assertEquals("The link set size did not match.", 0,
+                     linkService.getDeviceLinks(DeviceId.deviceId(deviceIdValue3)).size());
+
+        // test the getDeviceEgressLinks() method
+        assertEquals("The link set size did not match.", 1,
+                     linkService.getDeviceEgressLinks(DeviceId.deviceId(deviceIdValue1)).size());
+        assertEquals("The link set size did not match.", 1,
+                     linkService.getDeviceEgressLinks(DeviceId.deviceId(deviceIdValue2)).size());
+        assertEquals("The link set size did not match.", 0,
+                     linkService.getDeviceEgressLinks(DeviceId.deviceId(deviceIdValue3)).size());
+
+        // test the getDeviceIngressLinks() method
+        assertEquals("The link set size did not match.", 1,
+                     linkService.getDeviceIngressLinks(DeviceId.deviceId(deviceIdValue1)).size());
+        assertEquals("The link set size did not match.", 1,
+                     linkService.getDeviceIngressLinks(DeviceId.deviceId(deviceIdValue2)).size());
+        assertEquals("The link set size did not match.", 0,
+                     linkService.getDeviceIngressLinks(DeviceId.deviceId(deviceIdValue3)).size());
+
+        // test the getEgressLinks() method
+        assertEquals("The link set size did not match.", 1,
+                     linkService.getEgressLinks(src).size());
+        assertEquals("The link set size did not match.", 1,
+                     linkService.getEgressLinks(dst).size());
+        assertEquals("The link set size did not match.", 0,
+                     linkService.getEgressLinks(connectPoint).size());
+
+        // test the getIngressLinks() method
+        assertEquals("The link set size did not match.", 1,
+                     linkService.getIngressLinks(src).size());
+        assertEquals("The link set size did not match.", 1,
+                     linkService.getIngressLinks(dst).size());
+        assertEquals("The link set size did not match.", 0,
+                     linkService.getIngressLinks(connectPoint).size());
+    }
+
+    /**
+     * Tests the getLink() method using a null src connect point.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetLinkByNullSrc() {
+
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        VirtualDevice srcVirtualDevice =
+                manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue1));
+        VirtualDevice dstVirtualDevice =
+                manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+        ConnectPoint src = new ConnectPoint(srcVirtualDevice.id(), PortNumber.portNumber(1));
+        ConnectPoint dst = new ConnectPoint(dstVirtualDevice.id(), PortNumber.portNumber(2));
+        manager.createVirtualLink(virtualNetwork.id(), src, dst);
+        manager.createVirtualLink(virtualNetwork.id(), dst, src);
+
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getLink() method with a null src connect point.
+        linkService.getLink(null, dst);
+    }
+
+    /**
+     * Tests the getLink() method using a null dst connect point.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetLinkByNullDst() {
+
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        VirtualDevice srcVirtualDevice =
+                manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue1));
+        VirtualDevice dstVirtualDevice =
+                manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue2));
+        ConnectPoint src = new ConnectPoint(srcVirtualDevice.id(), PortNumber.portNumber(1));
+        ConnectPoint dst = new ConnectPoint(dstVirtualDevice.id(), PortNumber.portNumber(2));
+        manager.createVirtualLink(virtualNetwork.id(), src, dst);
+        manager.createVirtualLink(virtualNetwork.id(), dst, src);
+
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getLink() method with a null dst connect point.
+        linkService.getLink(src, null);
+    }
+
+    /**
+     * Tests querying for links using a null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetDeviceLinksByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getDeviceLinks() method with a null device identifier.
+        linkService.getDeviceLinks(null);
+    }
+
+    /**
+     * Tests querying for links using a null connect point.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetLinksByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getLinks() method with a null connect point.
+        linkService.getLinks(null);
+    }
+
+    /**
+     * Tests querying for device egress links using a null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetDeviceEgressLinksByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getDeviceEgressLinks() method with a null device identifier.
+        linkService.getDeviceEgressLinks(null);
+    }
+
+    /**
+     * Tests querying for device ingress links using a null device identifier.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetDeviceIngressLinksByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getDeviceIngressLinks() method with a null device identifier.
+        linkService.getDeviceIngressLinks(null);
+    }
+
+    /**
+     * Tests querying for egress links using a null connect point.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetEgressLinksByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getEgressLinks() method with a null connect point.
+        linkService.getEgressLinks(null);
+    }
+
+    /**
+     * Tests querying for ingress links using a null connect point.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testGetIngressLinksByNullId() {
+        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
+        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
+        LinkService linkService = manager.get(virtualNetwork.id(), LinkService.class);
+
+        // test the getIngressLinks() method with a null connect point.
+        linkService.getIngressLinks(null);
+    }
+
+    /**
+     * Core service test class.
+     */
+    private class TestCoreService extends CoreServiceAdapter {
+
+        @Override
+        public IdGenerator getIdGenerator(String topic) {
+            return new IdGenerator() {
+                private AtomicLong counter = new AtomicLong(0);
+
+                @Override
+                public long getNewId() {
+                    return counter.getAndIncrement();
+                }
+            };
+        }
+    }
+}
diff --git a/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkManagerTest.java b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkManagerTest.java
index 837b501..7c3f9f8 100644
--- a/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkManagerTest.java
+++ b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkManagerTest.java
@@ -57,10 +57,10 @@
  * Junit tests for VirtualNetworkManager.
  */
 public class VirtualNetworkManagerTest {
-    final String tenantIdValue1 = "TENANT_ID1";
-    final String tenantIdValue2 = "TENANT_ID2";
-    final String deviceIdValue1 = "DEVICE_ID1";
-    final String deviceIdValue2 = "DEVICE_ID2";
+    private final String tenantIdValue1 = "TENANT_ID1";
+    private final String tenantIdValue2 = "TENANT_ID2";
+    private final String deviceIdValue1 = "DEVICE_ID1";
+    private final String deviceIdValue2 = "DEVICE_ID2";
 
     private VirtualNetworkManager manager;
     private VirtualNetworkService virtualNetworkManagerService;