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Re: Header compression: header set diff

From: Patrick McManus <pmcmanus@mozilla.com>
Date: Thu, 21 Mar 2013 09:12:57 -0400
Message-ID: <CAOdDvNq8K52L1rOF8GR7pi4VDx+fOshO=Co7O+0YQTGUL9XMZw@mail.gmail.com>
To: RUELLAN Herve <Herve.Ruellan@crf.canon.fr>
Cc: "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
On Thu, Mar 21, 2013 at 8:50 AM, RUELLAN Herve
<Herve.Ruellan@crf.canon.fr> wrote:

> To better understand the impact of this choice of persisting the header set, we tested it inside HeaderDiff and saw a slight improvement of compaction for requests but also a slight(er) decrease of compaction for responses.

All else being equal (which is of course never true), compression
ratio of requests is more important than responses because the MUX
allows multiple requests to fit inside the cwnd (and thus avoid
scaling by rtt). The better the ratio, the greater the number of
transactions in 1-flight-mux. On the response side the headers are
mixed in with data frames which in many (but not all) scenarios
overhwelm the headers on a byte count basis - so the effect of header
compression is less likely to impact congestion control.
Received on Thursday, 21 March 2013 13:13:25 GMT

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