diff -u -r ns-3-dev/src/internet/model//udp-l4-protocol.cc workspace/src/ns-3-dev/src/internet/model//udp-l4-protocol.cc
--- ns-3-dev/src/internet/model//udp-l4-protocol.cc	2012-01-26 15:52:06.000000000 -0200
+++ workspace/src/ns-3-dev/src/internet/model//udp-l4-protocol.cc	2012-01-30 16:57:18.000000000 -0200
@@ -258,22 +258,13 @@
                      Ipv4Address saddr, Ipv4Address daddr, 
                      uint16_t sport, uint16_t dport)
 {
-  NS_LOG_FUNCTION (this << packet << saddr << daddr << sport << dport);
-
   UdpHeader udpHeader;
-  if(Node::ChecksumEnabled ())
-    {
-      udpHeader.EnableChecksums ();
-      udpHeader.InitializeChecksum (saddr,
-                                    daddr,
-                                    PROT_NUMBER);
-    }
+
   udpHeader.SetDestinationPort (dport);
   udpHeader.SetSourcePort (sport);
-
   packet->AddHeader (udpHeader);
 
-  m_downTarget (packet, saddr, daddr, PROT_NUMBER, 0);
+  Send (packet, saddr, daddr, sport, dport, 0);
 }
 
 void
@@ -283,18 +274,14 @@
 {
   NS_LOG_FUNCTION (this << packet << saddr << daddr << sport << dport << route);
 
-  UdpHeader udpHeader;
   if(Node::ChecksumEnabled ())
     {
+	  UdpHeader udpHeader;
+	  packet->PeekHeader(udpHeader);
+
       udpHeader.EnableChecksums ();
-      udpHeader.InitializeChecksum (saddr,
-                                    daddr,
-                                    PROT_NUMBER);
+      udpHeader.InitializeChecksum (saddr, daddr, PROT_NUMBER);
     }
-  udpHeader.SetDestinationPort (dport);
-  udpHeader.SetSourcePort (sport);
-
-  packet->AddHeader (udpHeader);
 
   m_downTarget (packet, saddr, daddr, PROT_NUMBER, route);
 }
diff -u -r ns-3-dev/src/internet/model//udp-socket-impl.cc workspace/src/ns-3-dev/src/internet/model//udp-socket-impl.cc
--- ns-3-dev/src/internet/model//udp-socket-impl.cc	2012-01-26 15:52:06.000000000 -0200
+++ workspace/src/ns-3-dev/src/internet/model//udp-socket-impl.cc	2012-01-30 17:02:45.000000000 -0200
@@ -31,6 +31,7 @@
 #include "udp-socket-impl.h"
 #include "udp-l4-protocol.h"
 #include "ipv4-end-point.h"
+#include "udp-header.h"
 #include <limits>
 
 NS_LOG_COMPONENT_DEFINE ("UdpSocketImpl");
@@ -440,6 +441,13 @@
       Ptr<Ipv4Route> route;
       Ptr<NetDevice> oif = m_boundnetdevice; //specify non-zero if bound to a specific device
       // TBD-- we could cache the route and just check its validity
+
+      // Patch - BUG 1111 - UDP header does not attached before RouteOutput
+      UdpHeader udpHeader;
+      udpHeader.SetSourcePort(m_endPoint->GetLocalPort ());
+      udpHeader.SetDestinationPort(port);
+      p->AddHeader(udpHeader);
+
       route = ipv4->GetRoutingProtocol ()->RouteOutput (p, header, oif, errno_); 
       if (route != 0)
         {
@@ -462,8 +470,9 @@
           header.SetSource (route->GetSource ());
           m_udp->Send (p->Copy (), header.GetSource (), header.GetDestination (),
                        m_endPoint->GetLocalPort (), port, route);
-          NotifyDataSent (p->GetSize ());
-          return p->GetSize ();
+
+          NotifyDataSent (p->GetSize () - udpHeader.GetSerializedSize());
+          return (p->GetSize () - udpHeader.GetSerializedSize());
         }
       else 
         {