[e2e] TCP in outer space

Jim Gettys jg at pa.dec.com
Fri Apr 13 07:59:34 PDT 2001

> Sender: end2end-interest-admin at postel.org
> From: Fred Baker <fred at cisco.com>
> Subject: Re: [e2e] TCP in outer space
> -----
material elided...
> But it really only gets rid of one round trip in a session that generally
> requires at least three or four, which seems like a pretty small
> optimization. An HTTP request for a web page could carry the HTTP GET data
> on the SYN packet, and the data coming in reply could be on the SYN-ACK,
> but if there is any loss at all in the network you are going to see some
> level of retransmission anyway, and the mean web page (10K, I'm told) is
> still going to take several segments and at least a couple of round trips.
> Email is a much deeper kettle of fish; sure, you could carry the EHELO on
> the SYN packet, but how much would that help with the succession of "From",
> "To", "Data", and "end of data" messages that SMTP carries?

You are falling for the classic mean versus median disease....

The mean and median are very different.

In fact, things tend to be bimodal in the web: small HTML documents,
and then large images or other transfers.

So you'd get, me thinks, good benefit from all this.

Not to mention the reduction in human perceptible latency: you
can't figure out what to fetch until you have the HTML in your hands,
which will tend to be the short initial transaction....
				- Jim

Jim Gettys
Technology and Corporate Development
Compaq Computer Corporation
jg at pa.dec.com

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