diff -r 8359b3ac1ab0 src/aodv/model/aodv-routing-protocol.cc
--- a/src/aodv/model/aodv-routing-protocol.cc	Fri Jun 03 10:54:07 2011 -0700
+++ b/src/aodv/model/aodv-routing-protocol.cc	Fri Jun 03 15:29:14 2011 -0700
@@ -105,7 +105,11 @@
   MyRouteTimeout (Time (2 * std::max (PathDiscoveryTime, ActiveRouteTimeout))),
   HelloInterval (Seconds (1)),
   AllowedHelloLoss (2),
-  DeletePeriod (Time (5 * std::max (ActiveRouteTimeout, HelloInterval))),
+  // The current implementation using hello messages to maintain connectivity
+  // Per RFC 3561
+  // DELETE_PERIOD must be at least ALLOWED_HELLO_LOSS * HELLO_INTERVAL
+  // TODO : Implement the case when EnableHello is set to False
+  DeletePeriod (2 * 1),
   NextHopWait (NodeTraversalTime + MilliSeconds (10)),
   TimeoutBuffer (2),
   BlackListTimeout (Time (RreqRetries * NetTraversalTime)),
@@ -182,6 +186,15 @@
                    TimeValue (Seconds (15)),
                    MakeTimeAccessor (&RoutingProtocol::DeletePeriod),
                    MakeTimeChecker ())
+    .AddAttribute (" DeletePeriod", "DeletePeriod is intended to provide an upper bound on the time for which an upstream node A "
+                   "can have a neighbor B as an active next hop for destination D, while B has invalidated the route to D."
+		   "WARNING: must be overridden for the case when EnableHello is set to False. To be implemented"
+// The current implementation using hello messages to maintain connectivity. Per RFC 3561 DELETE_PERIOD must be at least ALLOWED_HELLO_LOSS * HELLO_INTERVAL"
+//                    "can have a neighbor B as an active next hop for destination D, while B has invalidated the route to D."
+                   " = 2 * 1",
+                   TimeValue (Seconds (2)),
+                   MakeTimeAccessor (&RoutingProtocol::DeletePeriod),
+                   MakeTimeChecker ())
     .AddAttribute ("TimeoutBuffer", "Its purpose is to provide a buffer for the timeout so that if the RREP is delayed"
                    " due to congestion, a timeout is less likely to occur while the RREP is still en route back to the source.",
                    UintegerValue (2),
@@ -873,8 +886,11 @@
   ScheduleRreqRetry (dst);
   if (EnableHello)
     {
-      m_htimer.Cancel ();
-      m_htimer.Schedule (HelloInterval - Time (0.01 * MilliSeconds (UniformVariable ().GetInteger (0, 10))));
+      if(!m_htimer.IsRunning ()) 
+        {
+          m_htimer.Cancel ();
+          m_htimer.Schedule (HelloInterval - Time (0.01 * MilliSeconds (UniformVariable ().GetInteger (0, 10))));
+        }
     }
 }
 
@@ -1137,8 +1153,11 @@
 
   if (EnableHello)
     {
-      m_htimer.Cancel ();
-      m_htimer.Schedule (HelloInterval - Time (0.1 * MilliSeconds (UniformVariable ().GetInteger (0, 10))));
+      if (!m_htimer.IsRunning ())
+        {
+          m_htimer.Cancel ();
+          m_htimer.Schedule (HelloInterval - Time (0.1 * MilliSeconds (UniformVariable ().GetInteger (0, 10))));
+        }
     }
 }