Added more unit tests.
diff --git a/net/api/src/test/java/org/onlab/onos/net/link/DefaultLinkDescriptionTest.java b/net/api/src/test/java/org/onlab/onos/net/link/DefaultLinkDescriptionTest.java
new file mode 100644
index 0000000..2c69625
--- /dev/null
+++ b/net/api/src/test/java/org/onlab/onos/net/link/DefaultLinkDescriptionTest.java
@@ -0,0 +1,30 @@
+package org.onlab.onos.net.link;
+
+import org.junit.Test;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.PortNumber;
+
+import static org.junit.Assert.assertEquals;
+import static org.onlab.onos.net.DefaultLinkTest.cp;
+import static org.onlab.onos.net.DeviceId.deviceId;
+import static org.onlab.onos.net.Link.Type.DIRECT;
+import static org.onlab.onos.net.PortNumber.portNumber;
+
+/**
+ * Test of the default link description.
+ */
+public class DefaultLinkDescriptionTest {
+
+    private static final DeviceId DID1 = deviceId("of:foo");
+    private static final DeviceId DID2 = deviceId("of:bar");
+    private static final PortNumber P1 = portNumber(1);
+
+    @Test
+    public void basics() {
+        LinkDescription desc = new DefaultLinkDescription(cp(DID1, P1), cp(DID2, P1), DIRECT);
+        assertEquals("incorrect src", cp(DID1, P1), desc.src());
+        assertEquals("incorrect dst", cp(DID2, P1), desc.dst());
+        assertEquals("incorrect type", DIRECT, desc.type());
+    }
+
+}