Re: p1: Via and gateways

David Morris <dwm@xpasc.com> Sat, 20 April 2013 07:22 UTC

Return-Path: <ietf-http-wg-request@listhub.w3.org>
X-Original-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Delivered-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 94AE721F8D70 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Sat, 20 Apr 2013 00:22:42 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.509
X-Spam-Level:
X-Spam-Status: No, score=-4.509 tagged_above=-999 required=5 tests=[AWL=6.090, BAYES_00=-2.599, RCVD_IN_DNSWL_HI=-8]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PpCg-4U-hXR1 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Sat, 20 Apr 2013 00:22:41 -0700 (PDT)
Received: from frink.w3.org (frink.w3.org [128.30.52.56]) by ietfa.amsl.com (Postfix) with ESMTP id D70B221F89AF for <httpbisa-archive-bis2Juki@lists.ietf.org>; Sat, 20 Apr 2013 00:22:41 -0700 (PDT)
Received: from lists by frink.w3.org with local (Exim 4.72) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1UTS7s-0005yb-71 for ietf-http-wg-dist@listhub.w3.org; Sat, 20 Apr 2013 07:22:24 +0000
Resent-Date: Sat, 20 Apr 2013 07:22:24 +0000
Resent-Message-Id: <E1UTS7s-0005yb-71@frink.w3.org>
Received: from maggie.w3.org ([128.30.52.39]) by frink.w3.org with esmtp (Exim 4.72) (envelope-from <dwm@xpasc.com>) id 1UTS7p-0005xw-Bf for ietf-http-wg@listhub.w3.org; Sat, 20 Apr 2013 07:22:21 +0000
Received: from c2w3p-2.abacamail.com ([209.133.53.32]) by maggie.w3.org with esmtp (Exim 4.72) (envelope-from <dwm@xpasc.com>) id 1UTS7o-0006qv-3y for ietf-http-wg@w3.org; Sat, 20 Apr 2013 07:22:21 +0000
Received: from xpasc.com (unknown [68.164.244.188]) by c2w3p-2.abacamail.com (Postfix) with ESMTP id CEF3B406A5 for <ietf-http-wg@w3.org>; Sat, 20 Apr 2013 07:21:52 +0000 (UTC)
Received: from egate.xpasc.com (egate.xpasc.com [10.1.2.49]) by xpasc.com (8.13.8/8.13.8) with ESMTP id r3K7LqXq019755 for <ietf-http-wg@w3.org>; Sat, 20 Apr 2013 00:21:52 -0700
Date: Sat, 20 Apr 2013 00:21:52 -0700
From: David Morris <dwm@xpasc.com>
Reply-To: ietf@ietf.org
cc: "ietf-http-wg@w3.org Group" <ietf-http-wg@w3.org>
In-Reply-To: <F7810D5C-45A6-4D01-83ED-2A9AB5856813@mnot.net>
Message-ID: <alpine.LRH.2.01.1304200017490.18732@egate.xpasc.com>
References: <F7810D5C-45A6-4D01-83ED-2A9AB5856813@mnot.net>
User-Agent: Alpine 2.01 (LRH 1266 2009-07-14)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset="US-ASCII"
X-Milter-Version: master.1+13-gbab1945
X-AV-Type: clean
X-AV-Accuracy: exact
Received-SPF: pass client-ip=209.133.53.32; envelope-from=dwm@xpasc.com; helo=c2w3p-2.abacamail.com
X-W3C-Hub-Spam-Status: No, score=-2.6
X-W3C-Hub-Spam-Report: AWL=-3.826, MISSING_HEADERS=1.207, SPF_PASS=-0.001
X-W3C-Scan-Sig: maggie.w3.org 1UTS7o-0006qv-3y 326ca21616f67e9b33c029e52edc4f8d
X-Original-To: ietf-http-wg@w3.org
Subject: Re: p1: Via and gateways
Archived-At: <http://www.w3.org/mid/alpine.LRH.2.01.1304200017490.18732@egate.xpasc.com>
To: ietf-http-wg@w3.org
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/17396
X-Loop: ietf-http-wg@w3.org
Resent-Sender: ietf-http-wg-request@w3.org
Precedence: list
List-Id: <ietf-http-wg.w3.org>
List-Help: <http://www.w3.org/Mail/>
List-Post: <mailto:ietf-http-wg@w3.org>
List-Unsubscribe: <mailto:ietf-http-wg-request@w3.org?subject=unsubscribe>

On Sat, 20 Apr 2013, Mark Nottingham wrote:

> 
> p1 Section 2.3 says:
> 
> > However, an HTTP-to-HTTP gateway that wishes to interoperate with
> > third-party HTTP servers must conform to HTTP user agent requirements
> > on the gateway's inbound connection and must implement the Connection
> > (Section 6.1) and Via (Section 5.7.1) header fields for both
> > connections.
> 
> This means that accelerators and CDNs MUST generate a Via header on the
> outbound connection. This isn't widely practiced, and I'm not sure it's
> necessary. Comments?

I don't care about MUST, but I think the Via header can be useful for
problem determination. A smart content server could also adjust for
a detected accelerator and/or transcoder ... perhaps by avoiding
optimizations dependant on a direct connection and byte/byte transfer
between the client and the server.

So I'm very much in favor of keeping the Via: header.