Re: [MMUSIC] Congestion control

Martin Thomson <martin.thomson@gmail.com> Tue, 11 June 2013 18:16 UTC

Return-Path: <martin.thomson@gmail.com>
X-Original-To: mmusic@ietfa.amsl.com
Delivered-To: mmusic@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1D55D21F991F for <mmusic@ietfa.amsl.com>; Tue, 11 Jun 2013 11:16:14 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.45
X-Spam-Level:
X-Spam-Status: No, score=-2.45 tagged_above=-999 required=5 tests=[AWL=0.150, BAYES_00=-2.599, NO_RELAYS=-0.001]
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 DBiad+rfvqdH for <mmusic@ietfa.amsl.com>; Tue, 11 Jun 2013 11:16:13 -0700 (PDT)
Received: from mail-wi0-x232.google.com (mail-wi0-x232.google.com [IPv6:2a00:1450:400c:c05::232]) by ietfa.amsl.com (Postfix) with ESMTP id 649E621F98C3 for <mmusic@ietf.org>; Tue, 11 Jun 2013 11:16:12 -0700 (PDT)
Received: by mail-wi0-f178.google.com with SMTP id k10so1171223wiv.11 for <mmusic@ietf.org>; Tue, 11 Jun 2013 11:16:12 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=vMhUwTdXb6rLKHmKKClLRS8e6RgEGPxIZO3NT7J6Pm0=; b=nrQhRq+t+OY5p1BJw8w+SRCRemVJWT4eO4/mDjZ5S3BCoP3qACZ4vDuKhOPtWZqhAL ECu6xXMEb7lv11GHC/RWtbPOjvZ7fbw7axEc7GogMlwXAi91vCoUL46d1jetMawpa/YT fO02IckohTcV5nHmind2bXV9FV1GuQdn0vkj4N0adkS0FtwZ/4/Q6gUXN0q1ka4P3dcE 0oM5V6ZgQZRSrd4fUTILYzUAW0ALge+rBc93r0n95RiMe9zaIKOra42mry/k0KZ30Cx6 Z8ZejfcPM4SK0/W7r/pS58rX8/n2KRbwxyTrhmDd7FncFvvYKLGQKyfthu+v8opDLMQ1 k6ig==
MIME-Version: 1.0
X-Received: by 10.180.36.12 with SMTP id m12mr2195313wij.10.1370974571998; Tue, 11 Jun 2013 11:16:11 -0700 (PDT)
Received: by 10.194.60.46 with HTTP; Tue, 11 Jun 2013 11:16:11 -0700 (PDT)
In-Reply-To: <BLU404-EAS23506E27752A1E0E07558BC93850@phx.gbl>
References: <20130530185619.4124.56395.idtracker@ietfa.amsl.com> <51A87F91.2080500@jitsi.org> <51AEA08D.8090103@cisco.com> <BLU403-EAS336A4AA94CDB5E97170F9A5939F0@phx.gbl> <25B9903E-DC06-4BB0-92A1-C1E7A2AA569E@iii.ca> <BLU169-W609A2EAD331201B824EB6093980@phx.gbl> <4D8F5FFC-F89B-4A5B-8464-3EF20E7D67E9@iii.ca> <BLU169-W35E035EC4AC7AE5BBCCBBC93840@phx.gbl> <BAF96BD5-D167-4B78-AF92-DDB2DE780A32@iii.ca> <BLU404-EAS23506E27752A1E0E07558BC93850@phx.gbl>
Date: Tue, 11 Jun 2013 11:16:11 -0700
Message-ID: <CABkgnnXaAzaeqKOvt4jFyOrxeXr1K7Wc=9k4XL5RrWKGay2p9g@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: Bernard Aboba <bernard_aboba@hotmail.com>
Content-Type: text/plain; charset="UTF-8"
Cc: "mmusic@ietf.org" <mmusic@ietf.org>, Cullen Jennings <fluffy@iii.ca>
Subject: Re: [MMUSIC] Congestion control
X-BeenThere: mmusic@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Multiparty Multimedia Session Control Working Group <mmusic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/mmusic>, <mailto:mmusic-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/mmusic>
List-Post: <mailto:mmusic@ietf.org>
List-Help: <mailto:mmusic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mmusic>, <mailto:mmusic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 11 Jun 2013 18:16:14 -0000

On 11 June 2013 03:05, Bernard Aboba <bernard_aboba@hotmail.com> wrote:
> Also, earlier there was a discussion of using signaling vs. Magnus' codec operation point to control resolution, which in the case of spatial scaling would involve addition or removal of layers - and as I recall, signaling won.

I wasn't there for that discussion, but I can imagine that that
conclusion might have been not representative for a number of reasons.
 When you talk about "addition", then I believe that signaling is
necessary (unless that was already allowed in the session description
somehow).  However, removal isn't so clear cut.  "Removal" might be a
permanent thing, in which case, an argument could be made for
signaling.  Where "removal" is just stopping transmission due to
congestion (or other transient conditions), then I don't think that
that signaling is appropriate.

The objections to COP might also have been influenced by the IPR
declarations on the document.