diff --git a/src/point-to-point/model/point-to-point-net-device.cc b/src/point-to-point/model/point-to-point-net-device.cc
index bfa31fff6..df7b747ad 100644
--- a/src/point-to-point/model/point-to-point-net-device.cc
+++ b/src/point-to-point/model/point-to-point-net-device.cc
@@ -206,6 +206,16 @@ PointToPointNetDevice::ProcessHeader (Ptr<Packet> p, uint16_t& param)
   return true;
 }
 
+void
+PointToPointNetDevice::DoInitialize (void)
+{
+  NS_LOG_FUNCTION (this);
+  // A NetDeviceQueueInterface object must have been aggregated to this device
+  // by the traffic control layer
+  m_queueInterface = GetObject<NetDeviceQueueInterface> ();
+  NetDevice::DoInitialize ();
+}
+
 void
 PointToPointNetDevice::DoDispose ()
 {
@@ -280,18 +290,27 @@ PointToPointNetDevice::TransmitComplete (void)
   m_phyTxEndTrace (m_currentPkt);
   m_currentPkt = 0;
 
+  NS_ASSERT (m_queueInterface);
+  Ptr<NetDeviceQueue> txq = m_queueInterface->GetTxQueue (0);
+
   Ptr<QueueItem> item = m_queue->Dequeue ();
   if (item == 0)
     {
-      //
-      // No packet was on the queue, so we just exit.
-      //
+      NS_LOG_LOGIC ("No pending packets in device queue after tx complete");
+      txq->Wake ();
       return;
     }
 
   //
-  // Got another packet off of the queue, so start the transmit process agin.
+  // Got another packet off of the queue, so start the transmit process again.
+  // If the queue was stopped, start it again. Note that we cannot wake the upper
+  // layers because otherwise a packet is sent to the device while the machine
+  // state is busy, thus causing the assert in TransmitStart to fail.
   //
+  if (txq->IsStopped ())
+    {
+      txq->Start ();
+    }
   Ptr<Packet> p = item->GetPacket ();
   m_snifferTrace (p);
   m_promiscSnifferTrace (p);
@@ -511,6 +530,11 @@ PointToPointNetDevice::Send (
   const Address &dest, 
   uint16_t protocolNumber)
 {
+  NS_ASSERT (m_queueInterface);
+  Ptr<NetDeviceQueue> txq = m_queueInterface->GetTxQueue (0);
+
+  NS_ASSERT_MSG (!txq->IsStopped (), "Send should not be called when the device is stopped");
+
   NS_LOG_FUNCTION (this << packet << dest << protocolNumber);
   NS_LOG_LOGIC ("p=" << packet << ", dest=" << &dest);
   NS_LOG_LOGIC ("UID is " << packet->GetUid ());
@@ -551,8 +575,10 @@ PointToPointNetDevice::Send (
       return true;
     }
 
-  // Enqueue may fail (overflow)
+  // Enqueue may fail (overflow). Stop the tx queue, so that the upper layers
+  // do not send packets until there is room in the queue again.
   m_macTxDropTrace (packet);
+  txq->Stop ();
   return false;
 }
 
diff --git a/src/point-to-point/model/point-to-point-net-device.h b/src/point-to-point/model/point-to-point-net-device.h
index b43cb2f68..2ec402ce6 100644
--- a/src/point-to-point/model/point-to-point-net-device.h
+++ b/src/point-to-point/model/point-to-point-net-device.h
@@ -198,6 +198,8 @@ protected:
    */
   void DoMpiReceive (Ptr<Packet> p);
 
+  virtual void DoInitialize (void);
+
 private:
 
   /**
@@ -435,6 +437,7 @@ private:
   TracedCallback<Ptr<const Packet> > m_promiscSnifferTrace;
 
   Ptr<Node> m_node;         //!< Node owning this NetDevice
+  Ptr<NetDeviceQueueInterface> m_queueInterface;   //!< NetDevice queue interface
   Mac48Address m_address;   //!< Mac48Address of this NetDevice
   NetDevice::ReceiveCallback m_rxCallback;   //!< Receive callback
   NetDevice::PromiscReceiveCallback m_promiscCallback;  //!< Receive callback
diff --git a/src/point-to-point/test/point-to-point-test.cc b/src/point-to-point/test/point-to-point-test.cc
index 211e6584f..302549b4e 100644
--- a/src/point-to-point/test/point-to-point-test.cc
+++ b/src/point-to-point/test/point-to-point-test.cc
@@ -86,6 +86,11 @@ PointToPointTest::DoRun (void)
   a->AddDevice (devA);
   b->AddDevice (devB);
 
+  Ptr<NetDeviceQueueInterface> ifaceA = CreateObject<NetDeviceQueueInterface> ();
+  devA->AggregateObject (ifaceA);
+  Ptr<NetDeviceQueueInterface> ifaceB = CreateObject<NetDeviceQueueInterface> ();
+  devB->AggregateObject (ifaceB);
+
   Simulator::Schedule (Seconds (1.0), &PointToPointTest::SendOnePacket, this, devA);
 
   Simulator::Run ();