Re: [MMUSIC] bundle-11: BUNDLE accpeted, but RTCP Mux rejected

Christer Holmberg <christer.holmberg@ericsson.com> Wed, 08 October 2014 11:36 UTC

Return-Path: <christer.holmberg@ericsson.com>
X-Original-To: mmusic@ietfa.amsl.com
Delivered-To: mmusic@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id CD9DC1A02E3 for <mmusic@ietfa.amsl.com>; Wed, 8 Oct 2014 04:36:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.6
X-Spam-Level:
X-Spam-Status: No, score=-2.6 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, 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 moCe_fDu31gI for <mmusic@ietfa.amsl.com>; Wed, 8 Oct 2014 04:36:38 -0700 (PDT)
Received: from sessmg22.ericsson.net (sessmg22.ericsson.net [193.180.251.58]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 41EAC1A02DA for <mmusic@ietf.org>; Wed, 8 Oct 2014 04:36:37 -0700 (PDT)
X-AuditID: c1b4fb3a-f79da6d0000008c7-e3-543521c2de3d
Received: from ESESSHC003.ericsson.se (Unknown_Domain [153.88.253.124]) by sessmg22.ericsson.net (Symantec Mail Security) with SMTP id F8.7F.02247.2C125345; Wed, 8 Oct 2014 13:36:35 +0200 (CEST)
Received: from ESESSMB209.ericsson.se ([169.254.9.136]) by ESESSHC003.ericsson.se ([153.88.183.27]) with mapi id 14.03.0174.001; Wed, 8 Oct 2014 13:36:34 +0200
From: Christer Holmberg <christer.holmberg@ericsson.com>
To: "Stach, Thomas" <thomas.stach@unify.com>, Harald Alvestrand <harald@alvestrand.no>, "Cullen Jennings (fluffy)" <fluffy@cisco.com>
Thread-Topic: bundle-11: BUNDLE accpeted, but RTCP Mux rejected
Thread-Index: Ac/iRGIfWukm+VgKTsyCbXLuDZy5KwAGEVHgABwyUoAABzpZoA==
Date: Wed, 8 Oct 2014 11:36:33 +0000
Message-ID: <7594FB04B1934943A5C02806D1A2204B1D46E6EF@ESESSMB209.ericsson.se>
References: <F81CEE99482EFE438DAE2A652361EE121E224ECF@MCHP04MSX.global-ad.net> <7594FB04B1934943A5C02806D1A2204B1D46CF08@ESESSMB209.ericsson.se> <F81CEE99482EFE438DAE2A652361EE121E227C60@MCHP04MSX.global-ad.net>
In-Reply-To: <F81CEE99482EFE438DAE2A652361EE121E227C60@MCHP04MSX.global-ad.net>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [153.88.183.16]
Content-Type: multipart/alternative; boundary="_000_7594FB04B1934943A5C02806D1A2204B1D46E6EFESESSMB209erics_"
MIME-Version: 1.0
X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprNIsWRmVeSWpSXmKPExsUyM+Jvje5hRdMQgytXOSw6JrNZHOvrYrOY uvwxi8XJnduYHVg8rky4wuox5fdGVo8lS34yeWzvecwSwBLFZZOSmpNZllqkb5fAlXHx0AXm gilTGCu+3znD0sA4sZGxi5GTQ0LAROJZ32wWCFtM4sK99WxdjFwcQgJHGSVenf7NBOEsZpSY 2nWLuYuRg4NNwEKi+582SFxEoJ1R4v/RU6wg3cwCMhIzzjYygdjCAg4Scw9sA5sqIuAocfjN DbBeEQEniXMvvUHCLAIqEg8XLwMr4RXwleh5PZ0FYtd1Ronl1y6ygyQ4Bfwl9sw4CHYpI9B1 30+tYYLYJS5x68l8JoirBSSW7DnPDGGLSrx8/I8VwlaU2Hm2nRmiPl/i9NWdUMsEJU7OfMIy gVF0FpJRs5CUzUJSBhHXkViw+xMbhK0tsWzha2YY+8yBx0zI4gsY2VcxihanFhfnphsZ6aUW ZSYXF+fn6eWllmxiBMbmwS2/rXYwHnzueIhRgINRiYd3wSyTECHWxLLiytxDjNIcLErivAvP zQsWEkhPLEnNTk0tSC2KLyrNSS0+xMjEwSnVwMi6Jimr/qSj6BsbhgunLmb9VL9xPTE5z0Ne Ijk2qa3wou6NW5fWzHp+a+qStpN6vuevzNY/Yqj5aWlhtaFOj25U0VnxpE8flKV3u3DGaR6/ dIxp6aPGJw73ruYkRRdvYpD3bmC4cE3+1VzZP7/lDgcn71DYcNRe1FLOWmSv/rysBtXHZyoS Q5RYijMSDbWYi4oTAZMB53WuAgAA
Archived-At: http://mailarchive.ietf.org/arch/msg/mmusic/ZfAZ0HXlTeJRMlQmuYdoU4D6V_E
Cc: mmusic <mmusic@ietf.org>
Subject: Re: [MMUSIC] bundle-11: BUNDLE accpeted, but RTCP Mux rejected
X-BeenThere: mmusic@ietf.org
X-Mailman-Version: 2.1.15
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: Wed, 08 Oct 2014 11:36:41 -0000

Hi Thomas,

I suggest something like this:

In section 10.3.2.3:

OLD TEXT:

"If the answerer rejects usage of RTP/RTCP multiplexing within the
                BUNDLE group, it MUST NOT assign an SDP 'rtcp-mux' or SDP 'rtcp'
                attribute to any bundled "m=" line in the answer."

NEW TEXT:

"If the answerer rejects usage of RTP/RTCP multiplexing within the
                BUNDLE group, it MUST NOT assign an SDP 'rtcp-mux' or SDP 'rtcp'
                attribute to any bundled "m=" line in the answer. The answerer will,
                based on the port number of the selected offerer BUNDLE address,
                use the next higher (odd) destination port number [RFC3550] for
sending RTCP packets associated with a bundled "m=" line towards
the offerer,"


In section 10.3.2.4:

OLD TEXT:

                "If the answerer does not accept the usage of RTP/RTCP multiplexing
                [Section 10.3.2.3], the offerer MUST use separate 5-tuples for RTP
                and RTCP."

NEW TEXT:

                "If the answerer does not accept the usage of RTP/RTCP multiplexing
                [Section 10.3.2.3], the offerer MUST use separate 5-tuples for RTP
                and RTCP. The answerer will, based on the port number of the answerer
BUNDLE address, use the next higher (odd) destination port number [RFC3550]
for sending RTCP packets associated with a bundled "m=" line towards the
answerer."

Regards,

Christer




From: Stach, Thomas [mailto:thomas.stach@unify.com]
Sent: 8. lokakuuta 2014 13:06
To: Christer Holmberg; Harald Alvestrand; Cullen Jennings (fluffy)
Cc: mmusic
Subject: RE: bundle-11: BUNDLE accpeted, but RTCP Mux rejected


Christer,

From: Christer Holmberg [mailto:christer.holmberg@ericsson.com]
Sent: Dienstag, 7. Oktober 2014 20:35
To: Stach, Thomas; Harald Alvestrand; Cullen Jennings (fluffy)
Cc: mmusic
Subject: RE: bundle-11: BUNDLE accpeted, but RTCP Mux rejected

Hi Thomas,

>BUNDLE can be used separate from RFC5761 RTCP-Multiplexing.
>I can't find text in bundle-11 where the answerer would send its RTCP packets if it accepted BUNDLE, but rejected RTCP-muxing.
>I see two options:
>1. The answerer sends all RTCP packets to the shared RTP-port+1 of the negotiated shared address.
>2. The answerer sends the RTCP packets to separate ports based on the unique addresses in the m-lines of the offer?

Alternative 1) is correct. I guess we could add some text to clarify that.
[TS] Yes, please. The current text is not sufficiently clear.

>The offerer on the other hand will only receive a shared address. I assume it then has to send all its RTCP packets
>to the shared RTP-port+1 of the answerer.

Yes.

>Is my understanding correct or am I completely off-track?

Assuming my understanding is correct, your understanding is correct :)

>Supposed I'm correct, then independent from the response, I'm asking if there really is a use case for that.
>In case 1, one would have to demux the RTP streams and RTCP streams from two separate ports instead of a single port. How much implementation effort >is saved in that case?

I am not sure what you mean. Are you asking how much implementation effort is saved if you don't have to de-mux RTP and RTCP?
[TS] Yes.  I was questioning myself what benefit there is in not mandating RTCP-mux.
In the meantime I looked up again the discussion on "Q14" that led to having rtcp-mux optional. I agree with the outcome.
Thanks!

>In case 2 the RTCP handling at offerer and answerer is completely different. In addition, you still need "a lot" of RTCP ports and take advantage of only half >of the BUNDLE benefits.

Correct. But, case 2 is not applicable (unless the endpoints choose not to use BUNDLE to begin with, that is...).

Regards,

Christer