point-to-point-net-device.h
  class ErrorModel;
  
  /**
   * Error model for receive packet events
   */
  Ptr<ErrorModel> m_receiveErrorModel;
  

  void
PointToPointNetDevice::SetReceiveErrorModel (Ptr<ErrorModel> em)
{
  NS_LOG_FUNCTION (this << em);
  m_receiveErrorModel = em;
 

   .AddAttribute ("ReceiveErrorModel",
                   "The receiver error model used to simulate packet loss",
                   PointerValue (),
                   MakePointerAccessor (&PointToPointNetDevice::m_receiveErrorModel),
                   MakePointerChecker<ErrorModel> ())

void PointToPointNetDevice::Receive (Ptr<Packet> packet)
{
  NS_LOG_FUNCTION (this << packet);
  uint16_t protocol = 0;
  
  if (m_receiveErrorModel && m_receiveErrorModel->IsCorrupt (packet) )
    {
//  
// If we have an error model and it indicates that it is time to lose a
// corrupted packet, don't forward this packet up, let it go. 
// 
      m_dropTrace (packet);
     
  else
    {
//  
// Hit the receive trace hook, strip off the point-to-point protocol header
// and forward this packet up the protocol stack.
//     
      m_rxTrace (packet);
      ProcessHeader(packet, protocol);
      m_rxCallback (this, packet, protocol, GetRemote ());
      if (!m_promiscCallback.IsNull ())
        {           m_promiscCallback (this, packet, protocol, GetRemote (), 
                      GetAddress (), NetDevice::PACKET_HOST);
        
    

simple-error-model.cc

  // Error model
  // We want to add an error model to node 3's NetDevice
  // We can obtain a handle to the NetDevice via the channel and node
  // pointers
  Ptr<PointToPointNetDevice> nd3 = PointToPointTopology::GetNetDevice
    (n3, channel2);
  Ptr<ErrorModel> em = Create<ErrorModel> ();
  nd3->SetReceiveErrorModel (em);


bool
ErrorModel::DoCorrupt (Packet& p)
{
  NS_LOG_FUNCTION;
  NS_LOG_UNCOND("Corrupt!");
  return false;