bool
PointToPointNetDevice::Send (
  Ptr<Packet> packet,
  const Address &dest,
  uint16_t protocolNumber)
{
  NS_LOG_FUNCTION (this << packet << dest << protocolNumber);
  NS_LOG_LOGIC ("p=" << packet << ", dest=" << &dest);
  NS_LOG_LOGIC ("UID is " << packet->GetUid ());

  //
  // If IsLinkUp() is false it means there is no channel to send any packet
  // over so we just hit the drop trace on the packet and return an error.
  //
  if (IsLinkUp () == false)
    {
      m_macTxDropTrace (packet);
      return false;
    }

  //
  // Stick a point to point protocol header on the packet in preparation for
  // shoving it out the door.
  //
  AddHeader (packet, protocolNumber);

  m_macTxTrace (packet);

  //
  // We should enqueue and dequeue the packet to hit the tracing hooks.
  //
  if (m_queue->Enqueue (packet))
    {
      //
      // If the channel is ready for transition we send the packet right now
      //
      if (m_txMachineState == READY)
        {
          packet = m_queue->Dequeue ();
          m_snifferTrace (packet);
          m_promiscSnifferTrace (packet);
          return TransmitStart (packet);
        }
      return true;
    }

  // Enqueue may fail (overflow)
  m_macTxDropTrace (packet);
  return false;
}