Re: [MMUSIC] Bundle offer with different ports - where to expect media?

Martin Thomson <martin.thomson@gmail.com> Thu, 23 May 2013 21:42 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 AAE3A21F8E06 for <mmusic@ietfa.amsl.com>; Thu, 23 May 2013 14:42:11 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.59
X-Spam-Level:
X-Spam-Status: No, score=-4.59 tagged_above=-999 required=5 tests=[AWL=-0.991, BAYES_00=-2.599, RCVD_IN_DNSWL_LOW=-1]
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 QqbW2893JDMd for <mmusic@ietfa.amsl.com>; Thu, 23 May 2013 14:41:57 -0700 (PDT)
Received: from mail-lb0-f175.google.com (mail-lb0-f175.google.com [209.85.217.175]) by ietfa.amsl.com (Postfix) with ESMTP id 57A6F21F920B for <mmusic@ietf.org>; Thu, 23 May 2013 13:55:19 -0700 (PDT)
Received: by mail-lb0-f175.google.com with SMTP id v10so3867700lbd.6 for <mmusic@ietf.org>; Thu, 23 May 2013 13:55:18 -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=ysL0v7jsAO0lqWqMgUfSSbnGN/w87lg8fYWTH+4qFuQ=; b=ahjdhoqC2W+ZhCI8ZK7bcI+6d2jE84YToMG7G8S2guYwr0CxjNQVclUxxrKkzAkdUe qmxLSLiGj9ndMEyav47swM6biBCGUqFA+B7S2xS97jBf7qfIFrFD+zpPGmUv1ZMtXEh8 KfZQ8Uv7b66M1i7nvU/lcDTXNJQF91Fp8cc5V8UugpP8VP4ir6wn3S6qsn8Sre6e1TtP kCHcFpeZ/gBS3YWpNkKQvOpMaoMZDZPdH3troHNaagecAUMxRiQLHoYEJoNByXAgwoWA CzA7KEW0HQOzCmY5LkPdpfaNJD34fZ7ASJkfUBGb+mwfj+s4GDtGUzq5kepeF1qPwfae mOEA==
MIME-Version: 1.0
X-Received: by 10.112.154.35 with SMTP id vl3mr4561344lbb.55.1369342518249; Thu, 23 May 2013 13:55:18 -0700 (PDT)
Received: by 10.112.235.233 with HTTP; Thu, 23 May 2013 13:55:18 -0700 (PDT)
In-Reply-To: <C5E08FE080ACFD4DAE31E4BDBF944EB11350E214@xmb-aln-x02.cisco.com>
References: <7594FB04B1934943A5C02806D1A2204B1C374357@ESESSMB209.ericsson.se> <519A1336.9010001@jitsi.org> <9F33F40F6F2CD847824537F3C4E37DDF1159D127@MCHP04MSX.global-ad.net> <519A229D.7090204@jitsi.org> <7594FB04B1934943A5C02806D1A2204B1C374463@ESESSMB209.ericsson.se> <519A2768.5010904@alum.mit.edu> <CAPvvaa+A=LkYp9A+wENAABwCYaQcD0HVeX4o+O_16iJRPXZfNw@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B1C3744DC@ESESSMB209.ericsson.se> <CAPvvaaJsPNk1DAJXYoc8aUgZ0ZayV_8q84W=Mm7vwuRRGuwC-g@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B1C374572@ESESSMB209.ericsson.se> <519A3883.8060006@jitsi.org> <519A3C8F.3040309@alum.mit.edu> <519B343A.30704@jitsi.org> <519BB598.1030909@alum.mit.edu> <CAOJ7v-398_MiXLWjexU0Z0xQju3A-zWuQFkWkJSLPA5UEGAu+g@mail.gmail.com> <CABkgnnXqBzteoxH2qWBw1Xn9PHt2r___UCsp1Eoq4o8_VWvBZg@mail.gmail.com> <CAOJ7v-2xXb=uz3jBAKSXhyJ2mU9BGvYHZ=dkeKcZTWov7udWKQ@mail.gmail.com> <519CCE58.3000807@alum.mit.edu> <CAMvTgcdPZfBTyzoBZGCdJiHX+TaL3_T8+MnxH8+6vQPFTD4ZOA@mail.gmail.com> <CAOJ7v-1tmfy4Fu05ChcpbZT=bO-zr05qtOh9Lnw5bprbUEnoDw@mail.gmail.com> <C5E08FE080ACFD4DAE31E4BDBF944EB11350E214@xmb-aln-x02.cisco.com>
Date: Thu, 23 May 2013 13:55:18 -0700
Message-ID: <CABkgnnXgvEWtAs_yYu3ZZw0_TuFtgs_aOhpTrVaYZsfGd+hk+g@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: "Cullen Jennings (fluffy)" <fluffy@cisco.com>
Content-Type: text/plain; charset="UTF-8"
Cc: Christer Holmberg <christer.holmberg@ericsson.com>, mmusic <mmusic@ietf.org>, Paul Kyzivat <pkyzivat@alum.mit.edu>
Subject: Re: [MMUSIC] Bundle offer with different ports - where to expect media?
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: Thu, 23 May 2013 21:42:11 -0000

On 23 May 2013 06:41, Cullen Jennings (fluffy) <fluffy@cisco.com> wrote:
> On May 22, 2013, at 4:55 PM, Justin Uberti <juberti@google.com> wrote:
>
>> I think we could do this using the existing syntax, e.g.
>>
>> an offer of a=group:BUNDLE A B C would indicate that the offerer would prefer A, B, and C to be muxed onto A, and
>> an answer of a=group:BUNDLE C A would indicate that the answerer is going to mux C and A onto C, and send B unbundled.
>>
>
> I suspect several people are on the fence about using this approach or the first non rejected m-line in the bundle.
>
> Can anyone think of reasons why to pick one of the other of these two approaches ?

I was originally strongly in favor of basing transport parameter
choice solely on the order of m-lines in the SDP document.

However, after our discussion this morning, if we allow a previously
rejected m-line to be revived and added to a BUNDLE group, then the
rule stating that any existing transport is used would take precedence
over this.

But that sucks.  I have a better solution for this case. We should
require that previously negotiated m-lines cannot change their BUNDLE
affiliation.  That would prevent the old m-line from being re-added to
an existing BUNGLE.  A new m-line would be required.