Subject: Re: Serious longstanding problem with TCP
To: der Mouse <>
From: Perry E. Metzger <>
List: tech-net
Date: 11/22/1995 15:14:24
der Mouse writes:
> > For quite some time (I observed this in the summer too, but figured
> > it would go away), -current TCP has been performing very badly for
> > short file transfers.  [...]  You'll note that the second packet
> > [from server to client] is not MTU-sized - this causes the receiver
> > to not send an ack immediately.
> Isn't this what slow-start is all about?  Start with small packets and
> ramp up?

Actually, the problem isn't caused by slow start, but slow start will
inevitably cause problems to WWW.

> Perhaps slow-start needs to be rethought in view of WWW, which I think
> is probably the first protocol to carry on a lot of TCP conversations
> sequentially, sending only small amounts of data over each one.
> Personally, I think a preferable solution would be to redo the WWW
> protocol so it doesn't keep tearing down connections and creating new
> ones, precisely because connection setup and destruction has high
> overhead.

I agree with this for lots of reasons. HTTP is a horrible protocol,
and we shouldn't destroy all the nice TCP protocols that keep the
network humming along at high performance to accomodate it.