--- a/src/devices/p2p/p2p-net-device.cc	Thu Mar 29 16:55:42 2007 +0200
+++ b/src/devices/p2p/p2p-net-device.cc	Thu Mar 29 17:07:04 2007 +0200
@@ -350,8 +350,8 @@
     return m_queue;
 }
 
-PointToPointChannel* 
-PointToPointNetDevice::GetChannel(void) const 
+Channel* 
+PointToPointNetDevice::DoGetChannel(void) const 
 { 
     return m_channel;
 }

--- a/src/devices/p2p/p2p-net-device.h	Thu Mar 29 16:55:42 2007 +0200
+++ b/src/devices/p2p/p2p-net-device.h	Thu Mar 29 17:07:04 2007 +0200
@@ -33,8 +33,8 @@
 
 namespace ns3 {
 
+class Queue;
 class PointToPointChannel;
-class Queue;
 
 class PointToPointNetDevice : public NetDevice {
 public:
@@ -60,7 +60,6 @@
 
 protected:
   Queue* GetQueue(void) const; 
-  PointToPointChannel* GetChannel(void) const;
 
 private:
   virtual bool SendTo (Packet& p, const MacAddress& dest);
@@ -70,6 +69,8 @@
   void TransmitReadyEvent (void);
 
   virtual TraceResolver *DoCreateTraceResolver (TraceContext const &context);
+  virtual Channel *DoGetChannel(void) const;
+
 
   enum TxMachineState
     {

--- a/src/node/ipv4-loopback-interface.cc	Thu Mar 29 16:55:42 2007 +0200
+++ b/src/node/ipv4-loopback-interface.cc	Thu Mar 29 17:07:04 2007 +0200
@@ -27,40 +27,8 @@
 
 namespace ns3 {
 
-class Ipv4DummyNetDevice : public NetDevice
-{
-public:
-  Ipv4DummyNetDevice (Node *node);
-  Node *PeekNode (void) const;
-private:
-  virtual bool SendTo (Packet& p, const MacAddress& dest);
-  virtual TraceResolver *DoCreateTraceResolver (TraceContext const &context);
-};
-
-Ipv4DummyNetDevice::Ipv4DummyNetDevice (Node *node)
-  : NetDevice (node, MacAddress ())
-{
-  SetMtu (10000);
-}
-Node *
-Ipv4DummyNetDevice::PeekNode (void) const
-{
-  return GetNode ();
-}
-bool 
-Ipv4DummyNetDevice::SendTo (Packet& p, const MacAddress& dest)
-{
-  return false;
-}
-TraceResolver *
-Ipv4DummyNetDevice::DoCreateTraceResolver (TraceContext const &context)
-{
-  return new EmptyTraceResolver (context);
-}
-
-
 Ipv4LoopbackInterface::Ipv4LoopbackInterface (Node *node)
-  : Ipv4Interface (new Ipv4DummyNetDevice (node)),
+  : Ipv4Interface (0),
     m_node (node)
 {
 }

--- a/src/node/net-device.cc	Thu Mar 29 16:55:42 2007 +0200
+++ b/src/node/net-device.cc	Thu Mar 29 17:07:04 2007 +0200
@@ -169,6 +169,12 @@
   return DoCreateTraceResolver (context);
 }
 
+Channel *
+NetDevice::GetChannel (void) const
+{
+  return DoGetChannel ();
+}
+
 // Receive packet from below
 bool
 NetDevice::ForwardUp (Packet& packet)

--- a/src/node/net-device.h	Thu Mar 29 16:55:42 2007 +0200
+++ b/src/node/net-device.h	Thu Mar 29 17:07:04 2007 +0200
@@ -29,10 +29,10 @@
 
 namespace ns3 {
 
-class Ipv4L4Demux;
 class Node;
 class TraceResolver;
 class TraceContext;
+class Channel;
 
 /**
  * \brief Network layer to device interface
@@ -72,6 +72,13 @@
   TraceResolver *CreateTraceResolver (TraceContext const &context);
 
   /**
+   * \return the channel this NetDevice is connected to. The value
+   *         returned can be zero if the NetDevice is not yet connected
+   *         to any channel.
+   */
+  Channel *GetChannel (void) const;
+
+  /**
    * \return the current MacAddress of this interface.
    */
   MacAddress GetAddress (void) const;
@@ -218,6 +225,7 @@
   virtual bool SendTo (Packet& p, const MacAddress& dest) = 0;
 
   virtual TraceResolver *DoCreateTraceResolver (TraceContext const &context) = 0;
+  virtual Channel *DoGetChannel (void) const = 0;
   Node*         m_node;
   std::string   m_name;
   uint16_t      m_ifIndex;