tcp-westwood-nr.cc

NS2 simulation TCP westwood

	double sample_bwe_new=sample_bwe;
	double sample_bwe_old=last_bwe_sample_;
	double ack_delta=ack_interv;


	int Num_cicli;
	if (total_time_ < tau_/4.0) {
		Num_cicli = 0;
		ack_interv=total_time_;
		}
		else {
		Num_cicli = (int)(floor(((4.0*total_time_)/tau_)));
		ack_interv = total_time_-0.25*tau_*((double)(Num_cicli));
		}


		int i1;
  	for (i1=0;i1<(Num_cicli); i1++) 	{

		//if (m<0) {
			//sample_bwe=sample_bwe_old+m*pow((i1*tau_/4.0),interp_type_);
		//	}

		current_bwe_ = current_bwe_*(7.0/9.0)+(sample_bwe+last_bwe_sample_)/9.0;
		last_bwe_sample_ = sample_bwe;
		}

		if (ack_interv>0) {
		current_bwe_ = current_bwe_ * (2.0*tau_-ack_interv)/(2.0*tau_+ack_interv) +
		ack_interv*(sample_bwe_new+last_bwe_sample_)/(2.0*tau_+ack_interv);
		last_bwe_sample_ = sample_bwe_new;
		}




	total_time_=0.0;
	total_size_=0.0;
	}
	break;

  case 5:



	total_size_ = total_size_ + acked_size;
	total_time_ = total_time_ + ack_interv;

	if (((rtt_estimate >0)&&(total_time_>rtt_estimate))) {


        sample_bwe = total_size_/total_time_;

	current_bwe_=current_bwe_ * fr_alpha_ + sample_bwe*(1.0 - fr_alpha_);

	last_bwe_sample_ = sample_bwe;

	total_time_=0;
	total_size_=0;
	}
		break;

  case 6:



	total_size_ = total_size_ + acked_size;
	total_time_ = total_time_ + ack_interv;

	if (((rtt_estimate >0)&&(total_time_>rtt_estimate))) {


        sample_bwe = total_size_/total_time_;
	double sample_bwe1;
	sample_bwe1=0.5*(sample_bwe+last_bwe_sample_);

	current_bwe_=current_bwe_*fr_alpha_ + sample_bwe1*(1.0 - fr_alpha_);

	last_bwe_sample_ = sample_bwe;

	total_time_=0;
	total_size_=0;
	}
	break;
case 7:



	total_size_ = total_size_ + acked_size;
	total_time_ = total_time_ + ack_interv;

	if (((rtt_estimate >0)&&(total_time_>rtt_estimate))) {


        sample_bwe = total_size_/total_time_;

	double m=(sample_bwe-last_bwe_sample_)/pow(total_time_,interp_type_);

	double sample_bwe_new=sample_bwe;
	double sample_bwe_old=last_bwe_sample_;
	double ack_delta=ack_interv;


	int Num_cicli;
	if (total_time_ < tau_/4.0) {
		Num_cicli = 0;
		ack_interv=total_time_;
		}
		else {
		Num_cicli = (int)(floor(((4.0*total_time_)/tau_)));
		ack_interv = total_time_-0.25*tau_*((double)(Num_cicli));
		}


		int i1;
  	for (i1=0;i1<(Num_cicli); i1++) 	{


		sample_bwe=sample_bwe_old+m*pow((i1*tau_/4.0),interp_type_);

		current_bwe_ = current_bwe_*(7.0/9.0)+2.0*(sample_bwe)/9.0;
		last_bwe_sample_ = sample_bwe;
		}

		if (ack_interv>0) {
		current_bwe_ = current_bwe_ * (2.0*tau_-ack_interv)/(2.0*tau_+ack_interv) +
		2.0*ack_interv*(sample_bwe_new)/(2.0*tau_+ack_interv);
		last_bwe_sample_ = sample_bwe_new;
		}




	total_time_=0;
	total_size_=0;
	}

break;

  case 8:



	sample_bwe = acked_size/ack_interv;

	fr_alpha_=exp((-1.0*ack_interv/tau_));
	current_bwe_=current_bwe_*fr_alpha_ + sample_bwe*(1.0 - fr_alpha_);

	last_bwe_sample_ = sample_bwe;


break;

  case 9:



	total_size_ = total_size_ + acked_size;
	total_time_ = total_time_ + ack_interv;

	if (((rtt_estimate >0)&&(total_time_>rtt_estimate))) {


        sample_bwe = total_size_/total_time_;
	fr_alpha_=exp((-1.0*total_time_/tau_));
	current_bwe_=current_bwe_*fr_alpha_ + sample_bwe*(1.0 - fr_alpha_);

	last_bwe_sample_ = sample_bwe;

	total_time_=0;
	total_size_=0;
	}
	break;

case 10:



	total_size_ = total_size_ + acked_size;
	total_time_ = total_time_ + ack_interv;

	double ci;

	if (((rtt_estimate >0)&&(total_time_>rtt_estimate))) {

	//ci=cwnd_-(current_bwe_*min_rtt_estimate)/(8.0*(double)size_);

	if (qest_ > fr_a_) sample_bwe = total_size_/total_time_;
		else sample_bwe = last_bwe_sample_;

	fr_alpha_=exp((-1.0*total_time_/tau_));
	current_bwe_=current_bwe_*fr_alpha_ + sample_bwe*(1.0 - fr_alpha_);
	last_bwe_sample_ = sample_bwe;
	total_time_=0;
	total_size_=0;
	}




} // end of filter_type switch




double sstemp=(((current_bwe_*(min_rtt_estimate))/((double)(size_*8.0))));
//double sstemp1=0.9*qest_+(((current_bwe_*(min_rtt_estimate))/((double)(size_*8.0))));



#ifdef MYDEBUG
	hdr_ip *iph = hdr_ip::access(pkt);  
  	char *src_portaddr = Address::instance().print_portaddr(iph->sport());
	printf("sc%s: ack. no. %d at time %f, bwe=%f, cwnd = %d, ssthresh_ = %d\n",
	      src_portaddr, tcph->seqno_, fr_now, current_bwe_/1000000,
	      (int)cwnd_, (int)ssthresh_);
	printf("sc%s: now = %f, acked_size = %d, rxdiff = %f, last_ack_ = %d\n",
	         src_portaddr, fr_now, acked_size, (fr_now - lastackrx_), last_ack_);
	printf("sc%s: unaccounted_ = %d, fr_a_= %f, min_rtt_estimate = %f\n", 
			     src_portaddr, unaccounted_, fr_a_, min_rtt_estimate);
#endif
#ifdef MYDEBUG_RTT
	double f = t_rtt_ * tcp_tick_;
	printf("source %s: %f cwnd=%d	      bwe=%f	  rtt=%f\n", 
	      src_portaddr, fr_now, (int)cwnd_, current_bwe_/1000000, f);     
#endif	
#ifdef MYREPORT	
	hdr_ip *iph = hdr_ip::access(pkt);  
	char *src_portaddr = Address::instance().print_portaddr(iph->src());
	printf("%s    %f      %d      %f      %d\n", 
	      src_portaddr, fr_now, (int)cwnd_, current_bwe_/1000000,
	      (int)ssthresh_);        
#endif		

	lastackrx_ = fr_now;
}


/////
// recv()
void WestwoodNRTcpAgent::recv(Packet *pkt, Handler* h)
{
	// START BWE COMPUTATION
	bwe_computation(pkt);
	//double cwndapp,sstreshapp;
	//cwndapp=cwnd_;
	//sstreshapp=ssthresh_;
	NewRenoTcpAgent::recv(pkt,h);
	/*if ((cwnd_>cwndapp)&&(cwndapp<sstreshapp))
	{
	cwnd_=cwnd_+openadd_; //a more aggressive slow start
	send_much(0, 0, maxburst_);
	}*/
}

/////////////////// Added by MV
// these where originally in TcpAgent()

/////
// slowdown()
void
WestwoodNRTcpAgent::slowdown(int how)
{
	double win, halfwin, decreasewin;
	int slowstart = 0;
	double fr_now = Scheduler::instance().clock();
	// we are in slowstart for sure if cwnd < ssthresh
	if (cwnd_ < ssthresh_)
		slowstart = 1;
	// we are in slowstart - need to trace this event
	trace_event("SLOW_START");

        if (precision_reduce_) {
		halfwin = windowd() / 2;
                if (wnd_option_ == 6) {
                        /* binomial controls */
                        decreasewin = windowd() - (1.0-decrease_num_)*pow(windowd(),l_parameter_);
                } else
	 		decreasewin = decrease_num_ * windowd();
		win = windowd();
	} else  {
		int temp;
		temp = (int)(window() / 2);
		halfwin = (double) temp;
                if (wnd_option_ == 6) {
                        /* binomial controls */
                        temp = (int)(window() - (1.0-decrease_num_)*pow(window(),l_parameter_));
                } else
	 		temp = (int)(decrease_num_ * window());
		decreasewin = (double) temp;
		win = (double) window();
	}
	if (how & CLOSE_SSTHRESH_HALF)
		// For the first decrease, decrease by half
		// even for non-standard values of decrease_num_.
		if (first_decrease_ == 1 || slowstart ||
			last_cwnd_action_ == CWND_ACTION_TIMEOUT) {
			// Do we really want halfwin instead of decreasewin
			// after a timeout?
			ssthresh_ = (int) halfwin;
		} else {
			ssthresh_ = (int) decreasewin;
		}
        else if (how & THREE_QUARTER_SSTHRESH)
		if (ssthresh_ < 3*cwnd_/4)
			ssthresh_  = (int)(3*cwnd_/4);
	if (how & CLOSE_CWND_HALF)
		// For the first decrease, decrease by half
		// even for non-standard values of decrease_num_.
		if (first_decrease_ == 1 || slowstart || decrease_num_ == 0.5) {
			cwnd_ = halfwin;
		} else cwnd_ = decreasewin;
        else if (how & CWND_HALF_WITH_MIN) {
		// We have not thought about how non-standard TCPs, with
		// non-standard values of decrease_num_, should respond
		// after quiescent periods.
                cwnd_ = decreasewin;
                if (cwnd_ < 1)
                        cwnd_ = 1;
	}
	///
	else if (how & CLOSE_FASTER) {
    	// TCP Westwood
	// this might be critical what with the coarseness of the timer;
    	// keep in mind that TCP computes the timeout as
    	//              (#of ticks) * (tick_duration)
    	// We need to do away with the coarseness...


	double rtt_estimate = t_rtt_ * tcp_tick_;

	  if ((rtt_estimate <= min_rtt_estimate)&&(rtt_estimate > 0)) {
		   min_rtt_estimate = rtt_estimate;
		}

	 double sstemp=(((current_bwe_*(min_rtt_estimate))/((double)(size_*8.0))));
			if (sstemp < 2) sstemp = 2;
			ssthresh_ = (int)(sstemp);
			cwnd_ = 2;

	}
//printf("set timeout = %f%f\n", fr_now,ssthresh_);


	else if (how & CLOSE_CWND_RESTART)
		cwnd_ = int(wnd_restart_);
	else if (how & CLOSE_CWND_INIT)
		cwnd_ = int(wnd_init_);
	else if (how & CLOSE_CWND_ONE)
		cwnd_ = 1;
	else if (how & CLOSE_CWND_HALF_WAY) {
		// cwnd_ = win - (win - W_used)/2 ;
		cwnd_ = W_used + decrease_num_ * (win - W_used);
                if (cwnd_ < 1)
                        cwnd_ = 1;
	}
	if (ssthresh_ < 2)
		ssthresh_ = 2;
	if (how & (CLOSE_CWND_HALF|CLOSE_CWND_RESTART|CLOSE_CWND_INIT|CLOSE_CWND_ONE))
		cong_action_ = TRUE;

	fcnt_ = count_ = 0;
	if (first_decrease_ == 1)
		first_decrease_ = 0;
}

/////
// newack()
/*
 * Process a packet that acks previously unacknowleged data.
 */


void WestwoodNRTcpAgent::newack(Packet* pkt)
{
	hdr_tcp *tcph = hdr_tcp::access(pkt);
	myseqno_ = tcph->seqno_;
	//call parent newack
	NewRenoTcpAgent::newack(pkt);
}

///// 
// delay_bind_dispatch()
//Westwood binds
int
WestwoodNRTcpAgent::delay_bind_dispatch(const char *varName, const char *localName, TclObject *tracer)
{

	if (delay_bind(varName, localName, "lastackno_", &lastackno_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "lastackrx_", &lastackrx_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "fr_alpha_", &fr_alpha_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "filter_type_", &filter_type_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "tau_", &tau_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "mss_", &mss_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "current_bwe_", &current_bwe_, tracer)) return TCL_OK;
       	if (delay_bind(varName, localName, "last_bwe_sample_", &last_bwe_sample_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "unaccounted_", &unaccounted_, tracer)) return TCL_OK;
        if (delay_bind(varName, localName, "fr_a_", &fr_a_, tracer)) return TCL_OK;
        if (delay_bind(varName, localName, "min_rtt_estimate", &min_rtt_estimate, tracer)) return TCL_OK;
  	if (delay_bind(varName, localName, "myseqno_", &myseqno_, tracer)) return TCL_OK;
	
	// these where originally in NewRenoTcpAgent()
	if (delay_bind(varName, localName, "newreno_changes_", &newreno_changes_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "newreno_changes1_", &newreno_changes1_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "exit_recovery_fix_", &exit_recovery_fix_, tracer)) return TCL_OK;
	if (delay_bind(varName, localName, "partial_window_deflation_", &partial_window_deflation_, tracer)) return TCL_OK;

        return NewRenoTcpAgent::delay_bind_dispatch(varName, localName, tracer);
}

/* tickoff is the time since the clock last ticked when
 *  the packet we are using to compute the RTT was sent
 */

/* t_rtt_ is the number of ticks that have occurred so far,
 * starting from the tick BEFORE the packet was sent
 */