//make sure the buffer is logically sequenced

      if(next != m_bufferedData.end())

      {

        NS_ASSERT(next->first >= i->first + SequenceNumber(i->second->GetSize ()));

      }

      i = 

          m_bufferedData.find (tcpHeader.GetSequenceNumber () );

      UnAckData_t::iterator next = i;

      ++next;

      if(next != m_bufferedData.end())

        {

          NS_ASSERT(next->first >= i->first + SequenceNumber(i->second->GetSize ()));

        }

    }

  else if (tcpHeader.GetSequenceNumber () + SequenceNumber(s) > m_nextRxSequence)

    {//parial new data case, only part of the packet is new data

      s = tcpHeader.GetSequenceNumber () + SequenceNumber(s) - m_nextRxSequence; //how much new

      UnAckData_t::iterator next = m_bufferedData.upper_bound (m_nextRxSequence);

      if (next != m_bufferedData.end ())

      {

        SequenceNumber nextBufferedSeq = next->first;

        if (m_nextRxSequence + SequenceNumber(s) > nextBufferedSeq)

        {//tail end isn't all new either, trim enough off the end

          s = nextBufferedSeq - m_nextRxSequence;

        }

      }

      p = p->CreateFragment (m_nextRxSequence - tcpHeader.GetSequenceNumber (),s);

      SequenceNumber start = m_nextRxSequence;

      m_nextRxSequence += s;           // Advance next expected sequence

      SocketAddressTag tag;

      tag.SetAddress (fromAddress);

      p->AddTag (tag);

      //buffer the new fragment, it'll be read by call to Recv

      UnAckData_t::iterator i = m_bufferedData.find (start);

      if (i != m_bufferedData.end () ) //we found it already in the buffer

        {

          i->second = 0; // relase reference to already buffered

        }

      // Save for later delivery

      m_bufferedData[start] = p;

      m_rxAvailable += p->GetSize ();

      i = m_bufferedData.find (start);

      next = i;

      ++next;

      if(next != m_bufferedData.end())

      {

        NS_ASSERT(next->first >= i->first + SequenceNumber(i->second->GetSize ()));

      }