Re: [squid-users] "Accept-Encoding" header

Slava Bizyayev wrote:

> Here we see that Squid received the HTTP/1.1 request and transferred it as
> HTTP/1.0 to the following (MS) Proxy.
>
> As far as I understand the logics of proxy, it should make the reverse
> protocol transformation for outbound response. Am I right?

A HTTP proxy must downgrade requests and replies to the highest HTTP
version it supports. Squid is a HTTP/1.0 proxy with support for many
features from HTTP/1.1.

> The possible upgrade of the HTTP version seems very unsafe for the
> request processing. For example, MSIE-6.0 could be configured to work
> HTTP/1.0 for some special reason.

Any proxy doing upgrades of requests to a higher version than supported
by the requesting browser must also do downgrades of replies. Messy
business indeed, but needed for proper caching of results in HTTP/1.1.

If you consider that there may be a mix of HTTP/1.0 and HTTP/1.1 clients
accessing the same cache you see why a HTTP/1.1 proxy cache needs to
update all requests to HTTP/1.1, and why the same cache must also be
fully prepared to downgrade any cached replies (both cached and
uncached, no difference) to the level supported by the requestor..

Regards
Henrik
Received on Wed Jun 19 2002 - 16:18:48 MDT