--- a/examples/tcp-large-transfer.cc	Thu Mar 19 11:33:19 2009 -0700
+++ b/examples/tcp-large-transfer.cc	Mon Mar 23 11:26:39 2009 -0700
@@ -57,9 +57,14 @@
 void StartFlow(Ptr<Socket>, Ipv4Address, uint16_t);
 void WriteUntilBufferFull (Ptr<Socket>, uint32_t);
 
+static void 
+CwndTracer (uint32_t oldval, uint32_t newval)
+{
+  NS_LOG_INFO ("Moving cwnd from " << oldval << " to " << newval);
+}
+
 int main (int argc, char *argv[])
 {
-
   // Users may find it convenient to turn on explicit debugging
   // for selected modules; the below lines suggest how to do this
   //  LogComponentEnable("TcpL4Protocol", LOG_LEVEL_ALL);
@@ -67,9 +72,6 @@
   //  LogComponentEnable("PacketSink", LOG_LEVEL_ALL);
   //  LogComponentEnable("TcpLargeTransfer", LOG_LEVEL_ALL);
 
-
-  // Allow the user to override any of the defaults and the above
-  // Bind()s at run-time, via command-line arguments
   CommandLine cmd;
   cmd.Parse (argc, argv);
 
@@ -140,6 +142,9 @@
       Socket::CreateSocket (n0n1.Get (0), TcpSocketFactory::GetTypeId ());
   localSocket->Bind ();
 
+  // Trace changes to the congestion window
+  Config::ConnectWithoutContext ("/NodeList/0/$ns3::TcpL4Protocol/SocketList/0/CongestionWindow", MakeCallback (&CwndTracer));
+
   // ...and schedule the sending "Application"; This is similar to what an 
   // ns3::Application subclass would do internally.
   Simulator::ScheduleNow (&StartFlow, localSocket,

--- a/examples/tcp-nsc-lfn.cc	Thu Mar 19 11:33:19 2009 -0700
+++ b/examples/tcp-nsc-lfn.cc	Mon Mar 23 11:26:39 2009 -0700
@@ -43,6 +43,11 @@
 
 NS_LOG_COMPONENT_DEFINE ("TcpNscLfn");
 
+static void 
+CwndTracer (uint32_t oldval, uint32_t newval)
+{
+  NS_LOG_INFO ("Moving cwnd from " << oldval << " to " << newval);
+}
 
 int main (int argc, char *argv[])
 {
@@ -133,6 +138,10 @@
       clientApp.Stop (Seconds (runtime + 1.0 + i));
     }
 
+  // Trace changes to the congestion window
+  Config::ConnectWithoutContext ("/NodeList/1/$ns3::NscTcpL4Protocol/SocketList/0/CongestionWindow", 
+                                 MakeCallback (&CwndTracer));
+
   // This tells ns-3 to generate pcap traces.
   PointToPointHelper::EnablePcapAll ("tcp-nsc-lfn");
 

--- a/src/devices/point-to-point/point-to-point-net-device.cc	Thu Mar 19 11:33:19 2009 -0700
+++ b/src/devices/point-to-point/point-to-point-net-device.cc	Mon Mar 23 11:26:39 2009 -0700
@@ -167,6 +167,7 @@
 
 PointToPointNetDevice::~PointToPointNetDevice ()
 {
+  NS_LOG_FUNCTION_NOARGS ();
 }
 
   void 
@@ -226,8 +227,8 @@
   //
   NS_ASSERT_MSG(m_txMachineState == READY, "Must be READY to transmit");
   m_txMachineState = BUSY;
+  m_currentPkt = p;
   m_phyTxBeginTrace (m_currentPkt);
-  m_currentPkt = p;
 
   Time txTime = Seconds (m_bps.CalculateTxTime(p->GetSize()));
   Time txCompleteTime = txTime + m_tInterframeGap;

--- a/src/internet-stack/internet-stack.cc	Thu Mar 19 11:33:19 2009 -0700
+++ b/src/internet-stack/internet-stack.cc	Mon Mar 23 11:26:39 2009 -0700
@@ -54,6 +54,8 @@
   Ptr<UdpL4Protocol> udp = CreateObject<UdpL4Protocol> ();
   udp->SetNode (node);
   ipv4->Insert (udp);
+  node->AggregateObject (udp);
+
   Ptr<UdpSocketFactoryImpl> udpFactory = CreateObject<UdpSocketFactoryImpl> ();
   udpFactory->SetUdp (udp);
   node->AggregateObject (udpFactory);
@@ -66,6 +68,8 @@
   Ptr<Icmpv4L4Protocol> icmp = CreateObject<Icmpv4L4Protocol> ();
   icmp->SetNode (node);
   ipv4->Insert (icmp);
+  node->AggregateObject (icmp);
+
   Ptr<Ipv4RawSocketFactoryImpl> rawFactory = CreateObject<Ipv4RawSocketFactoryImpl> ();
   node->AggregateObject (rawFactory);
 }
@@ -76,8 +80,8 @@
   Ptr<Ipv4L3Protocol> ipv4 = node->GetObject<Ipv4L3Protocol> ();
   Ptr<TcpL4Protocol> tcp = CreateObject<TcpL4Protocol> ();
   tcp->SetNode (node);
-
   ipv4->Insert (tcp);
+  node->AggregateObject (tcp);
 
   Ptr<TcpSocketFactoryImpl> tcpFactory = CreateObject<TcpSocketFactoryImpl> ();
   tcpFactory->SetTcp (tcp);
@@ -114,6 +118,8 @@
   tcp->SetNscLibrary(soname);
   tcp->SetNode (node);
   ipv4->Insert (tcp);
+  node->AggregateObject (tcp);
+
   Ptr<NscTcpSocketFactoryImpl> tcpFactory = CreateObject<NscTcpSocketFactoryImpl> ();
   tcpFactory->SetTcp (tcp);
   node->AggregateObject (tcpFactory);

--- a/src/internet-stack/ipv4-l3-protocol.cc	Thu Mar 19 11:33:19 2009 -0700
+++ b/src/internet-stack/ipv4-l3-protocol.cc	Mon Mar 23 11:26:39 2009 -0700
@@ -152,15 +152,13 @@
   NS_LOG_FUNCTION (this);
   for (L4List_t::iterator i = m_protocols.begin(); i != m_protocols.end(); ++i)
     {
-      (*i)->Dispose ();
       *i = 0;
     }
   m_protocols.clear ();
 
-  for (Ipv4InterfaceList::const_iterator i = m_interfaces.begin (); i != m_interfaces.end (); ++i)
+  for (Ipv4InterfaceList::iterator i = m_interfaces.begin (); i != m_interfaces.end (); ++i)
     {
-      Ptr<Ipv4Interface> interface = *i;
-      interface->Dispose ();
+      *i = 0;
     }
   m_interfaces.clear ();
   m_node = 0;

--- a/src/internet-stack/nsc-tcp-l4-protocol.cc	Thu Mar 19 11:33:19 2009 -0700
+++ b/src/internet-stack/nsc-tcp-l4-protocol.cc	Mon Mar 23 11:26:39 2009 -0700
@@ -24,12 +24,13 @@
 #include "ns3/packet.h"
 #include "ns3/node.h"
 
+#include "ns3/object-vector.h"
+
 #include "tcp-header.h"
 #include "ipv4-end-point-demux.h"
 #include "ipv4-end-point.h"
 #include "ipv4-l3-protocol.h"
 #include "nsc-tcp-l4-protocol.h"
-#include "nsc-tcp-socket-impl.h"
 #include "nsc-sysctl.h"
 
 #include "tcp-typedefs.h"
@@ -70,6 +71,10 @@
                    ObjectFactoryValue (GetDefaultRttEstimatorFactory ()),
                    MakeObjectFactoryAccessor (&NscTcpL4Protocol::m_rttFactory),
                    MakeObjectFactoryChecker ())
+    .AddAttribute ("SocketList", "The list of sockets associated to this protocol.",
+                   ObjectVectorValue (),
+                   MakeObjectVectorAccessor (&NscTcpL4Protocol::m_sockets),
+                   MakeObjectVectorChecker<NscTcpSocketImpl> ())
     ;
   return tid;
 }
@@ -154,6 +159,14 @@
 NscTcpL4Protocol::DoDispose (void)
 {
   NS_LOG_FUNCTION (this);
+
+  for (std::vector<Ptr<NscTcpSocketImpl> >::iterator i = m_sockets.begin (); i != m_sockets.end (); i++)
+    {
+      *i = 0;
+    }
+  m_sockets.clear ();
+
+
   if (m_endPoints != 0)
     {
       delete m_endPoints;
@@ -173,6 +186,7 @@
   socket->SetNode (m_node);
   socket->SetTcp (this);
   socket->SetRtt (rtt);
+  m_sockets.push_back (socket);
   return socket;
 }
 

--- a/src/internet-stack/nsc-tcp-l4-protocol.h	Thu Mar 19 11:33:19 2009 -0700
+++ b/src/internet-stack/nsc-tcp-l4-protocol.h	Mon Mar 23 11:26:39 2009 -0700
@@ -31,6 +31,7 @@
 
 #include "ns3/timer.h"
 #include "sim_interface.h"
+#include "nsc-tcp-socket-impl.h"
 
 namespace ns3 {
 
@@ -116,6 +117,7 @@
   INetStack* m_nscStack;
   void *m_dlopenHandle;
   Timer m_softTimer;
+  std::vector<Ptr<NscTcpSocketImpl> > m_sockets;
 };
 
 }; // namespace ns3

--- a/src/internet-stack/nsc-tcp-socket-factory-impl.cc	Thu Mar 19 11:33:19 2009 -0700
+++ b/src/internet-stack/nsc-tcp-socket-factory-impl.cc	Mon Mar 23 11:26:39 2009 -0700
@@ -13,8 +13,8 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
+#include "nsc-tcp-l4-protocol.h"
 #include "nsc-tcp-socket-factory-impl.h"
-#include "nsc-tcp-l4-protocol.h"
 #include "ns3/socket.h"
 #include "ns3/assert.h"
 

--- a/src/internet-stack/tcp-l4-protocol.cc	Thu Mar 19 11:33:19 2009 -0700
+++ b/src/internet-stack/tcp-l4-protocol.cc	Mon Mar 23 11:26:39 2009 -0700
@@ -22,6 +22,7 @@
 #include "ns3/log.h"
 #include "ns3/nstime.h"
 #include "ns3/boolean.h"
+#include "ns3/object-vector.h"
 
 #include "ns3/packet.h"
 #include "ns3/node.h"
@@ -31,7 +32,6 @@
 #include "ipv4-end-point-demux.h"
 #include "ipv4-end-point.h"
 #include "ipv4-l3-protocol.h"
-#include "tcp-socket-impl.h"
 
 #include "tcp-typedefs.h"
 
@@ -334,6 +334,10 @@
                    BooleanValue (false),
                    MakeBooleanAccessor (&TcpL4Protocol::m_calcChecksum),
                    MakeBooleanChecker ())
+    .AddAttribute ("SocketList", "The list of sockets associated to this protocol.",
+                   ObjectVectorValue (),
+                   MakeObjectVectorAccessor (&TcpL4Protocol::m_sockets),
+                   MakeObjectVectorChecker<TcpSocketImpl> ())
     ;
   return tid;
 }
@@ -366,11 +370,18 @@
 TcpL4Protocol::DoDispose (void)
 {
   NS_LOG_FUNCTION_NOARGS ();
+  for (std::vector<Ptr<TcpSocketImpl> >::iterator i = m_sockets.begin (); i != m_sockets.end (); i++)
+    {
+      *i = 0;
+    }
+  m_sockets.clear ();
+
   if (m_endPoints != 0)
     {
       delete m_endPoints;
       m_endPoints = 0;
     }
+
   m_node = 0;
   Ipv4L4Protocol::DoDispose ();
 }
@@ -384,6 +395,7 @@
   socket->SetNode (m_node);
   socket->SetTcp (this);
   socket->SetRtt (rtt);
+  m_sockets.push_back (socket);
   return socket;
 }
 

--- a/src/internet-stack/tcp-l4-protocol.h	Thu Mar 19 11:33:19 2009 -0700
+++ b/src/internet-stack/tcp-l4-protocol.h	Mon Mar 23 11:26:39 2009 -0700
@@ -31,6 +31,7 @@
 #include "ipv4-l4-protocol.h"
 #include "ipv4-interface.h"
 
+#include "tcp-socket-impl.h"
 #include "tcp-header.h"
 #include "tcp-typedefs.h"
 
@@ -120,6 +121,7 @@
 
   bool m_goodChecksum;
   bool m_calcChecksum;
+  std::vector<Ptr<TcpSocketImpl> > m_sockets;
 };
 
 }; // namespace ns3