Re: [Roll] WGLC for draft-thubert-6man-flow-label-for-rpl-03

Brian E Carpenter <brian.e.carpenter@gmail.com> Wed, 30 July 2014 01:36 UTC

Return-Path: <brian.e.carpenter@gmail.com>
X-Original-To: roll@ietfa.amsl.com
Delivered-To: roll@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 0109D1A0AC7; Tue, 29 Jul 2014 18:36:45 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2
X-Spam-Level:
X-Spam-Status: No, score=-2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, SPF_PASS=-0.001] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WaYwcBlOfV8J; Tue, 29 Jul 2014 18:36:43 -0700 (PDT)
Received: from mail-ob0-x236.google.com (mail-ob0-x236.google.com [IPv6:2607:f8b0:4003:c01::236]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 942F81A04B8; Tue, 29 Jul 2014 18:36:43 -0700 (PDT)
Received: by mail-ob0-f182.google.com with SMTP id wm4so92488obc.41 for <multiple recipients>; Tue, 29 Jul 2014 18:36:43 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:organization:user-agent:mime-version:to:cc :subject:references:in-reply-to:content-type :content-transfer-encoding; bh=yrQ9LoTrf1Q4U9V34/5txGmGYjCRtxv9TwB0OnBOpb8=; b=WcysxmVcch3hDugj5Df2Q0QUtgu4644Rdnel+DkA0UbT5kR3bdCtVGhV/ATJX4I1CO lwwM+EhBznzy7HrmpPAz3J+KjeVkS24QqfNInzwOA9ewLtJddqDJu0hW0IH2cQaPk6WG +IOttgfG9G2gI2jcL+dGk5sO4MrLFnZza5O6sJagldQ6xxJ1ef4DDTaFd7ZqIz5hdc24 fKaFn513MXDKP15APANftOaQF7btdjHzV+JE89PJP/GY00BncQOx1Kdi//oJVe2odbbQ sv6CdGOaQN55xHLm7QdfuRJJ7pv+eIBfxG1unFrb/RFWVW5EWUoBcI4ZrXx9SJA5HmG3 e/OA==
X-Received: by 10.182.113.199 with SMTP id ja7mr556539obb.74.1406684203040; Tue, 29 Jul 2014 18:36:43 -0700 (PDT)
Received: from [172.24.60.8] (wireless-nat-21.auckland.ac.nz. [130.216.30.132]) by mx.google.com with ESMTPSA id d3sm3031667oez.5.2014.07.29.18.36.39 for <multiple recipients> (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 29 Jul 2014 18:36:42 -0700 (PDT)
Message-ID: <53D84C2C.9050709@gmail.com>
Date: Wed, 30 Jul 2014 13:36:44 +1200
From: Brian E Carpenter <brian.e.carpenter@gmail.com>
Organization: University of Auckland
User-Agent: Thunderbird 2.0.0.6 (Windows/20070728)
MIME-Version: 1.0
To: Philip Levis <pal@cs.stanford.edu>
References: <CAP+sJUeLa9r2otVv41ezg1Om--XzM84w3MOvCyn7bawDA7Oqgw@mail.gmail.com> <69656203-C009-4ABE-BCAD-17622058FEB9@cs.stanford.edu>
In-Reply-To: <69656203-C009-4ABE-BCAD-17622058FEB9@cs.stanford.edu>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Archived-At: http://mailarchive.ietf.org/arch/msg/roll/1WHxGkqbOwKuFKSdh_9wuU7q4_8
X-Mailman-Approved-At: Tue, 29 Jul 2014 22:01:33 -0700
Cc: Brian Haberman <brian@innovationslab.net>, "ipv6@ietf.org" <ipv6@ietf.org>, Michael Richardson <mcr+ietf@sandelman.ca>, roll <roll@ietf.org>, Ines Robles <mariainesrobles@googlemail.com>, Bob Hinden <bob.hinden@gmail.com>, Ole Troan <otroan@cisco.com>
Subject: Re: [Roll] WGLC for draft-thubert-6man-flow-label-for-rpl-03
X-BeenThere: roll@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: Routing Over Low power and Lossy networks <roll@ietf.org>
List-Id: Routing Over Low power and Lossy networks <roll.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/roll>, <mailto:roll-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/roll/>
List-Post: <mailto:roll@ietf.org>
List-Help: <mailto:roll-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/roll>, <mailto:roll-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 30 Jul 2014 01:36:45 -0000

On 30/07/2014 12:02, Philip Levis wrote:
...
> "This specification suggests that energy-saving is another
> compelling reason for a violation to the aforementioned
> rule."
> 
> makes the assumption that the energy saving is significant.
> Breaking the end-to-end nature of the flow label for some
> tiny saving seems like a mistake. 

I can't evaluate whether the energy saving is significant.
However, I don't have any deep faith in the e2e-ness of the
flow label. The reality (as RFC 6437 tries to recognise)
is that it's a mutable field, and is therefore untrustworthy
for e2e use. It has value for load balancing if all packets
of a given flow have the same label, whether the label is
set by the source or by a border device. For that reason,
I think the usage proposed in this draft is OK.

However, I do agree that at least a hand-waving estimate of
the % energy saving would be useful.

    Brian Carpenter