diff --git a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/NetworkGraphDiscoveryInterface.java b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/NetworkGraphDiscoveryInterface.java
index ffd95f5..87edb28 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/NetworkGraphDiscoveryInterface.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/NetworkGraphDiscoveryInterface.java
@@ -1,12 +1,63 @@
 package net.onrc.onos.ofcontroller.networkgraph;
 
+/**
+ * Interface used by the Topology Discovery module to write topology-related
+ * events.
+ */
 public interface NetworkGraphDiscoveryInterface {
-	public void putSwitchEvent(SwitchEvent switchEvent);
-	public void removeSwitchEvent(SwitchEvent switchEvent);
-	public void putPortEvent(PortEvent portEvent);
-	public void removePortEvent(PortEvent portEvent);
-	public void putLinkEvent(LinkEvent linkEvent);
-	public void removeLinkEvent(LinkEvent linkEvent);
-	public void putDeviceEvent(DeviceEvent deviceEvent);
-	public void removeDeviceEvent(DeviceEvent deviceEvent);
+    /**
+     * Switch discovered event.
+     *
+     * @param switchEvent the switch event.
+     */
+    public void putSwitchDiscoveryEvent(SwitchEvent switchEvent);
+
+    /**
+     * Switch removed event.
+     *
+     * @param switchEvent the switch event.
+     */
+    public void removeSwitchDiscoveryEvent(SwitchEvent switchEvent);
+
+    /**
+     * Port discovered event.
+     *
+     * @param portEvent the port event.
+     */
+    public void putPortDiscoveryEvent(PortEvent portEvent);
+
+    /**
+     * Port removed event.
+     *
+     * @param portEvent the port event.
+     */
+    public void removePortDiscoveryEvent(PortEvent portEvent);
+
+    /**
+     * Link discovered event.
+     *
+     * @param linkEvent the link event.
+     */
+    public void putLinkDiscoveryEvent(LinkEvent linkEvent);
+
+    /**
+     * Link removed event.
+     *
+     * @param linkEvent the link event.
+     */
+    public void removeLinkDiscoveryEvent(LinkEvent linkEvent);
+
+    /**
+     * Device discovered event.
+     *
+     * @param deviceEvent the device event.
+     */
+    public void putDeviceDiscoveryEvent(DeviceEvent deviceEvent);
+
+    /**
+     * Device removed event.
+     *
+     * @param deviceEvent the device event.
+     */
+    public void removeDeviceDiscoveryEvent(DeviceEvent deviceEvent);
 }