Re: [MMUSIC] BUNDLE Weekly Summary: Assumptions

Martin Thomson <martin.thomson@gmail.com> Fri, 10 May 2013 22:24 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 BB08C21F93C6 for <mmusic@ietfa.amsl.com>; Fri, 10 May 2013 15:24:28 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.559
X-Spam-Level:
X-Spam-Status: No, score=-2.559 tagged_above=-999 required=5 tests=[AWL=0.041, 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 zeZRj7jAsygy for <mmusic@ietfa.amsl.com>; Fri, 10 May 2013 15:24:19 -0700 (PDT)
Received: from mail-wi0-x22c.google.com (mail-wi0-x22c.google.com [IPv6:2a00:1450:400c:c05::22c]) by ietfa.amsl.com (Postfix) with ESMTP id DE03321F91A5 for <mmusic@ietf.org>; Fri, 10 May 2013 15:24:18 -0700 (PDT)
Received: by mail-wi0-f172.google.com with SMTP id hm14so1096492wib.11 for <mmusic@ietf.org>; Fri, 10 May 2013 15:23:52 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type; bh=vq967PjdMYFzw40RP6L2iHt4AVdg2gDcN05+wHsMhkI=; b=x2V4Kc1E9hx2L6yDxsmVs8ut3VAoPeDYo0oMwVt81bapZ7XzKfRKGPstuBwoG38np4 zslfHOAncrLK2+QHlSm9Eyg9ixepEQrTXK3kD29vpxsuiTSwwlcVXGePEEiort3F/Zd/ 6ZvelTMXF5qLtbYr/R1diyDJpWAJa6gULLxihnfWRN+3lqxdnfT1h/sr2WRr8dxtjJT/ LUAlJSM+PttMxHCvfIVby3rjSvPMeQaFTuC2nMJfJu//xyOAozQo2dGB03q9Vydoe0Hy JTEwtBJGVkYGT6dn8IxvCvCWDYkYDFQ5yhnYLrI18VCnOHjqZ6JPpFLAn44m6PYi6w9m h3ng==
MIME-Version: 1.0
X-Received: by 10.194.61.10 with SMTP id l10mr27351226wjr.32.1368224632672; Fri, 10 May 2013 15:23:52 -0700 (PDT)
Received: by 10.194.33.102 with HTTP; Fri, 10 May 2013 15:23:52 -0700 (PDT)
In-Reply-To: <CABcZeBODcyo-JXqs6EZ-F5BY_TaM94+eu+UqNApFnTNjpehUzA@mail.gmail.com>
References: <7594FB04B1934943A5C02806D1A2204B1C36B485@ESESSMB209.ericsson.se> <C5E08FE080ACFD4DAE31E4BDBF944EB1134DEF4B@xmb-aln-x02.cisco.com> <CABcZeBMrgaHGXFi_NRk+znsT-AGnRS5EDLgFhZgGA+VG81BhZw@mail.gmail.com> <CABkgnnW=4zNgauXc-=pv9j9zGdVntmb=K22wcRr77wfQc-6J3w@mail.gmail.com> <CABcZeBODcyo-JXqs6EZ-F5BY_TaM94+eu+UqNApFnTNjpehUzA@mail.gmail.com>
Date: Fri, 10 May 2013 15:23:52 -0700
Message-ID: <CABkgnnVd7LuH81gO_U9scY5sf_7zOZozyMhuxn-xiPHgMn_hFQ@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: Eric Rescorla <ekr@rtfm.com>
Content-Type: text/plain; charset="UTF-8"
Cc: "Cullen Jennings (fluffy)" <fluffy@cisco.com>, "mmusic@ietf.org" <mmusic@ietf.org>, Christer Holmberg <christer.holmberg@ericsson.com>
Subject: Re: [MMUSIC] BUNDLE Weekly Summary: Assumptions
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: Fri, 10 May 2013 22:24:53 -0000
X-List-Received-Date: Fri, 10 May 2013 22:24:53 -0000

On 10 May 2013 15:17, Eric Rescorla <ekr@rtfm.com> wrote:
> On Fri, May 10, 2013 at 3:16 PM, Martin Thomson <martin.thomson@gmail.com>
> wrote:
>>
>> On 10 May 2013 15:05, Eric Rescorla <ekr@rtfm.com> wrote:
>> > I'm sorry to be slow today, but can you point me to the specific MUST
>> > NOT in
>> > RFC 5888.
>>
>> I struggled to find it too.  It's in 9.2:
>>
>>    SIP entities refuse media streams by setting the port to zero in the
>>    corresponding "m" line. "a=group" lines MUST NOT contain
>>    identification-tags that correspond to "m" lines with the port set to
>>    zero.
>
> This feels like something we could relax for the offer.

Absolutely.  It seems a little arbitrary.  That said, I'd like to
understand why the MUST NOT exists.  Of the groupings I understand, I
can't think of a reason not to allow negotiated-off lines, but I'm
prepared to be surprised.