diff --git a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEventHandler.java b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEventHandler.java
index 29deb94..23b2f28 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEventHandler.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/flowmanager/FlowEventHandler.java
@@ -33,7 +33,11 @@
 import org.slf4j.LoggerFactory;
 
 /**
- * Class for implementing the Path Computation and Path Maintenance.
+ * Class for FlowPath Maintenance.
+ * This class listens for FlowEvents to:
+ * - Maintain a local cache of the Network Topology.
+ * - Detect FlowPaths impacted by Topology change.
+ * - Recompute impacted FlowPath using cached Topology.
  */
 class FlowEventHandler extends Thread implements IFlowEventHandlerService {
     /** The logger. */
@@ -386,6 +390,8 @@
 	// Test whether the Flow Path needs to be recomputed
 	//
 	switch (flowPath.flowPathType()) {
+	case FP_TYPE_UNKNOWN:
+	    return false;		// Can't recompute on Unknown FlowType
 	case FP_TYPE_SHORTEST_PATH:
 	    break;
 	case FP_TYPE_EXPLICIT_PATH:
diff --git a/src/main/java/net/onrc/onos/ofcontroller/topology/ShortestPath.java b/src/main/java/net/onrc/onos/ofcontroller/topology/ShortestPath.java
index dabe916..f187c27 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/topology/ShortestPath.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/topology/ShortestPath.java
@@ -24,7 +24,8 @@
 import com.tinkerpop.blueprints.Vertex;
 
 /**
- * A class for implementing the Shortest Path in a topology.
+ * Class to calculate a shortest DataPath between 2 SwitchPorts
+ * based on hops in Network Topology.
  */
 public class ShortestPath {
     /**
diff --git a/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java b/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
index ffe806a..c0e04f2 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/topology/TopologyManager.java
@@ -24,7 +24,10 @@
 import org.slf4j.LoggerFactory;
 
 /**
- * A class for implementing Topology Network Service.
+ * A class for obtaining Topology Snapshot
+ * and PathComputation.
+ *
+ * TODO: PathComputation part should be refactored out to separate class.
  */
 public class TopologyManager implements IFloodlightModule,
 					ITopologyNetService {