> So you have to keep sending it data in order for it not to restart?
No, this is only one of the conditions. The other half is the last time a
segment is received. If the interval between the send time and the last
received time is greater than 1 RTO, and the data to be sent is new data,
restart slow start. Also note that snd_cwnd is reset to 1 MSS at send
time. As long as the server does not send anything during the time the client
is parsing the page, snd_cwnd won't be changed. Then a new request comes
in, the server responds by sending new data. It does the check and since a
segment is just received, the idle time check fails and TCP will not restart
slow start.
> PS - there's debate on whether this is the correct implementation of the
> intent of the slow-start restart anyway. The idea is that if data isn't
> ackd for a while, you _can_ burst into the net at the line rate, and
> you need to avoid that.
Yes, the implementation may not refect what it is intended. But I guess
the question now is what the behaviour of current implementations is.
....
> At best, the window slams inbetween each user request. Which
> is still a loss.
>
> What am I missing?
I guess it is the fact that window is changed only at send time. So the
window will not shut down between requests. This is an implementation
artifact, btw.
K. Poon
[email protected]
This archive was generated by hypermail 2b29 : Mon Feb 14 2000 - 16:14:29 EST