Re: TCP RTT esimates

[Yuri Pryadkin <yuri@who.isi.edu>]

> > 	if (t_srtt_ != 0) {
> > 		register short delta;
> > >>>>		delta = t_rtt_ - (t_srtt_ >> T_SRTT_BITS);	// d = (m - a0)
> > 		if ((t_srtt_ += delta) <= 0)	// a1 = 7/8 a0 + 1/8 m
> > 			t_srtt_ = 1;
> > 
> > Where t_srtt_ is the smoothed(average) round trip time, and t_rtt_ is the
> > current round trip time sample.
> > 
> > According to this code, the final value of t_srtt_ is 7/8 of the previous
> > t_srtt_ + the new round trip time sample t_rtt_.  It should be 7/8 of the 
> > previous t_srtt_ + 1/8 of rtt_.
> 
> t_srtt_ is 8 * "smoothed round trip time" 
> its easier to maintain it that way.. a little more presicion and less
> shifts.

BTW, it doesn't seem necessary to check if (t_srtt_+= delta) <= 0.