[Stox] stox-media: format parameter translation

Jonathan Lennox <jonathan@vidyo.com> Thu, 09 January 2014 17:22 UTC

Return-Path: <jonathan@vidyo.com>
X-Original-To: stox@ietfa.amsl.com
Delivered-To: stox@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id EC8681AE4B4 for <stox@ietfa.amsl.com>; Thu, 9 Jan 2014 09:22:15 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.131
X-Spam-Level:
X-Spam-Status: No, score=-1.131 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_SORBS_WEB=0.77, SPF_PASS=-0.001] autolearn=no
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 C1DfYON724KA for <stox@ietfa.amsl.com>; Thu, 9 Jan 2014 09:22:15 -0800 (PST)
Received: from server209.appriver.com (server209d.appriver.com [8.31.233.119]) by ietfa.amsl.com (Postfix) with ESMTP id D1D251AE4B8 for <stox@ietf.org>; Thu, 9 Jan 2014 09:22:14 -0800 (PST)
X-Note-AR-ScanTimeLocal: 1/9/2014 12:22:03 PM
X-Policy: GLOBAL - vidyo.com
X-Primary: jonathan@vidyo.com
X-Note: This Email was scanned by AppRiver SecureTide
X-Virus-Scan: V-
X-Note-SnifferID: 0
X-Note: TCH-CT/SI:0-84/SG:2 1/9/2014 12:21:59 PM
X-GBUdb-Analysis: 0, 162.209.16.214, Ugly c=0.782655 p=-0.975855 Source White
X-Signature-Violations: 0-0-0-4042-c
X-Note-419: 15.6003 ms. Fail:0 Chk:1345 of 1345 total
X-Note: SCH-CT/SI:0-1345/SG:1 1/9/2014 12:21:57 PM
X-Note: Spam Tests Failed:
X-Country-Path: ->UNKNOWN->LOCAL
X-Note-Sending-IP: 162.209.16.214
X-Note-Reverse-DNS:
X-Note-Return-Path: jonathan@vidyo.com
X-Note: User Rule Hits:
X-Note: Global Rule Hits: G327 G328 G329 G330 G334 G335 G445
X-Note: Encrypt Rule Hits:
X-Note: Mail Class: VALID
X-Note: Headers Injected
Received: from [162.209.16.214] (HELO mail.vidyo.com) by server209.appriver.com (CommuniGate Pro SMTP 6.0.2) with ESMTPS id 62168828 for stox@ietf.org; Thu, 09 Jan 2014 12:22:03 -0500
Received: from 492132-EXCH1.vidyo.com ([fe80::50:56ff:fe85:4f77]) by 492133-EXCH2.vidyo.com ([fe80::250:56ff:fe85:4a71%11]) with mapi id 14.03.0146.000; Thu, 9 Jan 2014 11:22:02 -0600
From: Jonathan Lennox <jonathan@vidyo.com>
To: "stox@ietf.org" <stox@ietf.org>
Thread-Topic: stox-media: format parameter translation
Thread-Index: AQHPDV9PVnx5eBwDn0i//6+EvMAtCQ==
Date: Thu, 9 Jan 2014 17:22:02 +0000
Message-ID: <1CFAA181-4E37-42EF-A5B4-70737C697B9E@vidyo.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [160.79.219.114]
Content-Type: text/plain; charset="us-ascii"
Content-ID: <820258A62BDF214F8B0BB1C0D754A8A4@vidyo.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Subject: [Stox] stox-media: format parameter translation
X-BeenThere: stox@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: SIP-TO-XMPP Working Group discussion list <stox.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/stox>, <mailto:stox-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/stox/>
List-Post: <mailto:stox@ietf.org>
List-Help: <mailto:stox-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/stox>, <mailto:stox-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 09 Jan 2014 17:22:16 -0000

This is the issue I brought up at the Interim -- I'll try to put it in writing.

The point I raised is that the stox-media draft's section on format parameter translation should try to focus on media types which are actually used by existing, deployed Jingle clients, since this is probably a relatively small set.  The important question is which payload formats in use by existing Jingle clients have SDP fmtp formats that don't follow the normal semicolon-separated parameter model.

I of course haven't done a full inventory of such payload formats, but two that seem reasonably likely and I think should be particularly called out are:

audio/telephone-event: RFC 4733: the fmtp contains the value of an implicit "events" parameter.

audio/red: RFC 2198, with its media type registration in RFC 3555: the fmtp is the payload types of the encompassed formats.  The RFC 3555 definition of the actual media type parameters is weird (in an attempt to make it self-contained), and I doubt that any Jingle client that does RED would actually use it that way. So we need to figure out what any actual Jingle implementations do.

Does anyone have a reasonably-authoritative list of which RTP payload formats are supported by existing Jingle clients?  Does anyone know of any other real-world usage of codecs that have unusual fmtp encodings?  Someone on the call mentioned that they thought that Speex's was weird, but as far as I can tell, it's a normal semicolon-separated encoding.