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 0ba23dd..19fe0a7 100644
--- a/src/main/java/net/onrc/onos/core/topology/DeviceImpl.java
+++ b/src/main/java/net/onrc/onos/core/topology/DeviceImpl.java
@@ -62,4 +62,15 @@
     boolean removeAttachmentPoint(Port port) {
         return this.attachmentPoints.remove(port);
     }
+
+
+    /**
+     * Returns the type of topology object.
+     *
+     * @return the type of the topology object
+     */
+    @Override
+    public String getType() {
+        throw new UnsupportedOperationException("Not implemented yet");
+    }
 }
diff --git a/src/main/java/net/onrc/onos/core/topology/LinkImpl.java b/src/main/java/net/onrc/onos/core/topology/LinkImpl.java
index 4c7e1c5..d0276d1 100644
--- a/src/main/java/net/onrc/onos/core/topology/LinkImpl.java
+++ b/src/main/java/net/onrc/onos/core/topology/LinkImpl.java
@@ -96,4 +96,15 @@
                 getCapacity(),
                 getDstPort().toString());
     }
+
+
+    /**
+     * Returns the type of topology object.
+     *
+     * @return the type of the topology object
+     */
+    @Override
+    public String getType() {
+        throw new UnsupportedOperationException("Not implemented yet");
+    }
 }
diff --git a/src/main/java/net/onrc/onos/core/topology/PortImpl.java b/src/main/java/net/onrc/onos/core/topology/PortImpl.java
index 792d9f1..9332764 100644
--- a/src/main/java/net/onrc/onos/core/topology/PortImpl.java
+++ b/src/main/java/net/onrc/onos/core/topology/PortImpl.java
@@ -114,4 +114,15 @@
                 getSwitch().getDpid(),
                 getNumber());
     }
+
+
+    /**
+     * Returns the type of topology object.
+     *
+     * @return the type of the topology object
+     */
+    @Override
+    public String getType() {
+        throw new UnsupportedOperationException("Not implemented yet");
+    }
 }
diff --git a/src/main/java/net/onrc/onos/core/topology/SwitchImpl.java b/src/main/java/net/onrc/onos/core/topology/SwitchImpl.java
index ad13a79..9457cb5 100644
--- a/src/main/java/net/onrc/onos/core/topology/SwitchImpl.java
+++ b/src/main/java/net/onrc/onos/core/topology/SwitchImpl.java
@@ -140,4 +140,14 @@
     public String toString() {
         return dpid.toString();
     }
+
+    /**
+     * Returns the type of topology object.
+     *
+     * @return the type of the topology object
+     */
+    @Override
+    public String getType() {
+        throw new UnsupportedOperationException("Not implemented yet");
+    }
 }
diff --git a/src/main/java/net/onrc/onos/core/topology/TopologyObject.java b/src/main/java/net/onrc/onos/core/topology/TopologyObject.java
index 2dfd613..cdf51bd 100644
--- a/src/main/java/net/onrc/onos/core/topology/TopologyObject.java
+++ b/src/main/java/net/onrc/onos/core/topology/TopologyObject.java
@@ -1,10 +1,11 @@
 package net.onrc.onos.core.topology;
 
 
+
 /**
  * Base class for Topology Objects.
  */
-public class TopologyObject {
+public abstract class TopologyObject {
 
     /**
      * Topology instance this object belongs to.
@@ -20,4 +21,13 @@
         this.topology = topology;
     }
 
+
+    /**
+     * Returns the type of topology object.
+     *
+     * @return the type of the topology object
+     */
+    public abstract String getType();
+
+
 }