Attachment #1408 for bug #1405

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Time RttMeanDeviation::RetransmitTimeout ()
{
  NS_LOG_FUNCTION (this);

  // the default is 1 second, if there is not enough samples or the rtt is smaller than 1.
  Time retval = Time::FromInteger (1, Time::S);

  // if not enough samples returns 1, as especified at (2.1)  -> RFC 6298
  if (m_nSamples != 0)
    {
      if (m_nSamples == 1) // (2.2) -> RFC 6298
        {
    	  m_srtt = m_currentEstimatedRtt.ToDouble (Time::S);
    	  m_rttVar = m_srtt/2;
    	  retval = (retval.ToDouble (Time::S) > 4*m_rttVar) ? retval : Time::FromDouble (4*m_rttVar,  Time::S);
    	  retval = Time::FromDouble (m_rttVar,  Time::S) + retval;
        }
      else
        { // (2.3) -> RFC 6298
    	  m_rttVar = 0.75 * m_rttVar + 0.25 * abs(m_srtt - m_currentEstimatedRtt.ToDouble (Time::S));
    	  m_srtt = 0.875 * m_srtt + (0.125 * m_currentEstimatedRtt.ToDouble (Time::S));
       	  retval = (retval.ToDouble (Time::S) > 4*m_rttVar) ? retval : Time::FromDouble (4*m_rttVar,  Time::S);
       	  retval = Time::FromDouble (m_srtt,  Time::S) + retval;
         }
    }
  return (retval > m_minRto ? retval : m_minRto);  //  (2.4)  -> RFC 6298
    {
      int64_t temp = m_currentEstimatedRtt.ToInteger (Time::S) + 4 * m_variance.ToInteger (Time::S);
      retval = Time::FromInteger (temp, Time::S);
    }
  NS_LOG_DEBUG ("RetransmitTimeout:  return " << (retval > m_minRto ? retval.GetSeconds () : m_minRto.GetSeconds ()));
  return (retval > m_minRto ? retval : m_minRto);  // return maximum
}

Ptr<RttEstimator> RttMeanDeviation::Copy () const

(-)a/src/internet/model/rtt-estimator.h (+2 lines)

Lines 145-150	Link Here

145

protected:

145

protected:

146

  Time         m_currentEstimatedRtt;     // Current estimate

146

  Time         m_currentEstimatedRtt;     // Current estimate

147

  Time         m_minRto;                  // minimum value of the timeout

147

  Time         m_minRto;                  // minimum value of the timeout

148

  double       m_srtt;                    // smoothed round-trip time (RFC 6298)

149

  double       m_rttVar;				  // round-trip time variation (RFC 6298)

148

  uint32_t     m_nSamples;                // Number of samples

150

  uint32_t     m_nSamples;                // Number of samples

149

  uint16_t     m_multiplier;              // RTO Multiplier

151

  uint16_t     m_multiplier;              // RTO Multiplier

150

};

152

};




  header.SetWindowSize (AdvertisedWindowSize ());
  AddOptions (header);
  if (m_retxEvent.IsExpired () )
    {
	  // Schedules retransmit
      if (m_cnCount == 0)
        { // No more connection retries, give up
          NS_LOG_LOGIC ("Transmission failed.");
          CloseAndNotify ();
          m_rtt->Reset (); //According to recommendation -> RFC 6298
          return 0;
        }
      else
        { // Exponential backoff of connection time out
    	  int backoffCount = 0x1 << (m_cnRetries - m_cnCount);
          m_rto = m_rto * backoffCount;
          m_cnCount--;
        }

      if (m_rto.Get ().GetSeconds () > 60)
        { // (2.5)-> RFC 6298
    	  m_rto = Time::FromDouble (60,  Time::S);
        } else if (m_state == SYN_SENT && m_rto.Get ().GetSeconds () < 3)
        	{ // (5.7)-> RFC 6298
        		m_rto = Time::FromDouble (3,  Time::S);
        	}

      NS_LOG_LOGIC (this << " SendDataPacket Schedule ReTxTimeout at time " <<
                    Simulator::Now ().GetSeconds () << " to expire at time " <<
                    (Simulator::Now () + m_rto.Get ()).GetSeconds ());

      m_retxEvent = Simulator::Schedule (m_rto, &TcpSocketBase::ReTxTimeout, this);
    }
  NS_LOG_LOGIC ("Send packet via TcpL4Protocol with flags 0x" << std::hex << static_cast<uint32_t> (flags) << std::dec);

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