[Sip] G723.1H and G723.1L SDP negotiation
"Elison Niven" <elison.niven@matrixtelesol.com> Fri, 26 February 2010 08:55 UTC
Return-Path: <elison.niven@matrixtelesol.com>
X-Original-To: sip@core3.amsl.com
Delivered-To: sip@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix)
with ESMTP id 2BB5C3A84FD for <sip@core3.amsl.com>;
Fri, 26 Feb 2010 00:55:47 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: 3.24
X-Spam-Level: ***
X-Spam-Status: No,
score=3.24 tagged_above=-999 required=5 tests=[BAYES_50=0.001,
HOST_EQ_STATIC=1.172, RCVD_NUMERIC_HELO=2.067]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com
[127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 3j3MbN2Oiqik for
<sip@core3.amsl.com>; Fri, 26 Feb 2010 00:55:46 -0800 (PST)
Received: from UrlSunMail2.dellwebserver.com (34.27.354a.static.theplanet.com
[74.53.39.52]) by core3.amsl.com (Postfix) with ESMTP id 46CF23A7B03 for
<sip@ietf.org>; Fri, 26 Feb 2010 00:55:46 -0800 (PST)
Received: from 115.118.161.162.static-ttsl-hyderabad.vsnl.net.in
[115.118.161.162] by UrlSunMail2.dellwebserver.com with SMTP;
Fri, 26 Feb 2010 02:57:46 -0600
Received: from Internet10 [192.168.50.52] by Proxy+ with ESMTP for
<sip@ietf.org>; Fri, 26 Feb 2010 14:20:45 +0530
From: "Elison Niven" <elison.niven@matrixtelesol.com>
To: <sip@ietf.org>
Date: Fri, 26 Feb 2010 14:22:35 +0530
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
X-Mailer: Microsoft Office Outlook, Build 11.0.5510
Thread-Index: Acq2wQpdXdt1KNGqThqAcwL/LnWZFQ==
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5512
X-Cyberoam-Version: 9.5.8.52
X-Cyberoam-smtpxy-version: 1.0.5.3
X-Cyberoam-Proto: SMTP
X-Cyberoam-AV-Policy: None
X-Cyberoam-AS-Policy: Global Spam Policy
Message-Id: <20100226085546.46CF23A7B03@core3.amsl.com>
X-Mailman-Approved-At: Sun, 28 Feb 2010 19:19:01 -0800
Subject: [Sip] G723.1H and G723.1L SDP negotiation
X-BeenThere: sip@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: Session Initiation Protocol <sip.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/sip>,
<mailto:sip-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/sip>
List-Post: <mailto:sip@ietf.org>
List-Help: <mailto:sip-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/sip>,
<mailto:sip-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 26 Feb 2010 10:04:52 -0000
I apologize for posting to this list as I already posted this on SIP
implementers list but somehow this seems to be the better place to ask.
Hi List,
I know this has been discussed and asked a lot of times in the past but
still I find no affirmative solution.
For a UA that supports both G7231-H and G7231-L, SHOULD it specify both the
codecs in the offer that it sends?
If the UA is willing to specify both the codecs in the offer that it sends
(because it specifies two different codecs in its user interface), what
should be the method of specifying the codecs in the SDP body?
I find two possible ways of specifying both the codecs in the offer:
Case 1: Both codecs use different payload types, one of them uses a dynamic
payload type.
m = audio 8000 RTP/AVP 4 97
m = rtpmap:4 G723/8000
m = fmtpmap:4 bitrate=5.3
m = rtpmap:97 G723/8000
m = fmtpmap:97 bitrate=6.3
Case 2: Both codecs use the same static payload type.
m = audio 8000 RTP/AVP 4 4
m = rtpmap:4 G723/8000
m = fmtpmap:4 bitrate=5.3
m = rtpmap:4 G723/8000
m = fmtpmap:4 bitrate=6.3
Which of the above SDP offers seems valid?
Suppose I receive an answer from UA2 to the offer in Case 1 as:
m = audio 8000 RTP/AVP 4
m = rtpmap:4 G723/8000
m = fmtpmap:4 bitrate=5.3
What should be the payload of the packets that UA2 sends? Should it be 4 or
97?
Best Regards,
Elison
- [Sip] G723.1H and G723.1L SDP negotiation Elison Niven
- Re: [Sip] G723.1H and G723.1L SDP negotiation Kevin P. Fleming