Re: [rtcweb] Making progress on the signaling discussion (NB: Action items enclosed!)
Roman Shpount <roman@telurix.com> Wed, 12 October 2011 16:49 UTC
Return-Path: <roman@telurix.com>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 829DF21F8CFA for <rtcweb@ietfa.amsl.com>; Wed, 12 Oct 2011 09:49:04 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.976
X-Spam-Level:
X-Spam-Status: No, score=-2.976 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, FM_FORGED_GMAIL=0.622, HTML_MESSAGE=0.001, 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 r6W5Cr8rzq3I for <rtcweb@ietfa.amsl.com>; Wed, 12 Oct 2011 09:49:03 -0700 (PDT)
Received: from mail-vx0-f172.google.com (mail-vx0-f172.google.com [209.85.220.172]) by ietfa.amsl.com (Postfix) with ESMTP id DE88F21F8B52 for <rtcweb@ietf.org>; Wed, 12 Oct 2011 09:49:02 -0700 (PDT)
Received: by vcbfo11 with SMTP id fo11so920817vcb.31 for <rtcweb@ietf.org>; Wed, 12 Oct 2011 09:49:02 -0700 (PDT)
Received: by 10.220.191.203 with SMTP id dn11mr2238383vcb.16.1318438142234; Wed, 12 Oct 2011 09:49:02 -0700 (PDT)
Received: from mail-qy0-f179.google.com (mail-qy0-f179.google.com [209.85.216.179]) by mx.google.com with ESMTPS id hl5sm599642vdb.18.2011.10.12.09.49.01 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 12 Oct 2011 09:49:01 -0700 (PDT)
Received: by qyk33 with SMTP id 33so237413qyk.10 for <rtcweb@ietf.org>; Wed, 12 Oct 2011 09:49:00 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.68.32.162 with SMTP id k2mr2137994pbi.132.1318438140587; Wed, 12 Oct 2011 09:49:00 -0700 (PDT)
Received: by 10.68.47.40 with HTTP; Wed, 12 Oct 2011 09:49:00 -0700 (PDT)
In-Reply-To: <9E790044-DE19-46DD-89D8-C4F2973F8D65@phonefromhere.com>
References: <CA+9kkMBi9BzDu=WOq3RG-o5nbfnUTftDg3LRBU3DFh=Kc4W5ZQ@mail.gmail.com> <CALiegfmYgQ+yb=pDp1J2_PVa1SkxTOuaUCM02Vt6-iGabwif1g@mail.gmail.com> <CA+9kkMCUTiPO3eASjn0mbRA9YCF6TMmGGOjQ4NkVkvzVMN39Gg@mail.gmail.com> <CALiegfnx=qoS_pqyC45WVEYEFqj-3eP9g_kyhAUaOO6He_UEfw@mail.gmail.com> <CA+9kkMCibnPLrEq1234bUMXpiKBK0+22mqwYOM__CpcO2nOayg@mail.gmail.com> <CALiegfms2bt-WPtMeosFQz3-aSf2L6mfX+i68tw45sSgix561Q@mail.gmail.com> <4E8D6507.8000707@ericsson.com> <CALiegf=VyViX2arp0gr0dK4WN_jv=bjwP0LUAxRf=quTxrYrUQ@mail.gmail.com> <CALiegfn15szv-2yXeWptWjsQC2CwVODg_X90gD4odZkCR0LzvA@mail.gmail.com> <4E955775.10206@alvestrand.no> <CABRok6n6UA_nFfLzQ4K+H0+idspEsymW29OZH0J5q1ewF3PpRw@mail.gmail.com> <4E956526.2090604@alvestrand.no> <380E325E-A7EF-489A-AA24-0270224FC87A@phonefromhere.com> <4E957C55.9020706@alvestrand.no> <13C2526B-E7B1-408C-BD1D-EC5E8C8F6472@phonefromhere.com> <4E95871F.9010605@alvestrand.no> <E21755ED-205F-4D80-BB97-CF32E989EB3F@phonefromhere.com> <4E959D48.3090401@mozilla.com> <9E790044-DE19-46DD-89D8-C4F2973F8D65@phonefromhere.com>
Date: Wed, 12 Oct 2011 12:49:00 -0400
Message-ID: <CAD5OKxvORBxJk=5oAeWjUdMgq9pr7eePOnKana4VtwVEHFNGNg@mail.gmail.com>
From: Roman Shpount <roman@telurix.com>
To: rtcweb@ietf.org
Content-Type: multipart/alternative; boundary="bcaec520e4f3072f2704af1ccdf7"
Subject: Re: [rtcweb] Making progress on the signaling discussion (NB: Action items enclosed!)
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Real-Time Communication in WEB-browsers working group list <rtcweb.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rtcweb>
List-Post: <mailto:rtcweb@ietf.org>
List-Help: <mailto:rtcweb-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 12 Oct 2011 16:49:04 -0000
As far as I can see from this discussion there are several different items for consensus: 1. The API level: I think most of the people on the list agree that API should deal with media streams and media stream descriptions, i.e. should be as low level as possible without implementing actual RTP. There are few people here who argue for a higher level API that would allow to setup connection using some sort of higher level signalling protocol which will deal with individual stream setup in a manner transparent to a developer, but from what a lot of people on the list (including me) believe this can be implemented in JavaScript and does not need to be standardized. 2. API Semantics: I would say that API should be complete enough to implement everything that is currently supported by Offer/Answer and SIP signalling. It does not have to be offer/answer and can allow for new negotiation scenarios, but all the current scenarios, including forking, remote target SDP updates should be supported. I think RTC should provide a framework that would allow to implement all the current VoIP offer/answer negotiation flows. I don't think that we can ignore some of those flows even though some of the people on the list argue against it saying that this flows are specific for PSTN, or caused by SIP design flaw, or some other corner case of exiting offer/answer model. 3. Signaling Offer and Answer Format: Some people argue for direct use of SDP. Others argue for using JavaScript object or set of API methods to define the same. The main argument for using JavaScipt object/API methods would be that it will make it easier to manipulate session description from JavaScript. The main argument for using SDP is simpler interoperability with existing VoIP solutions. I would strongly argue for JavaScipt object/API primarily based on the fact that SDP is not enough to fully define the media parameters. Typically all the non-negotiated media stream parameters in VoIP solutions are defined from device configuration. We will need an API convey those preferences to RTC implementation which means a set of custom APIs on top of SDP. If we are doing custom APIs for media, we might as well make one that covers all the features. This being said, I would also argue that we need to have an API that can be used with new codecs implemented by the browser without explicitly extending the JavaScript signaling code. The current proposed API assumes that JavaScript code understands the meaning of all the codec parameters to negotiate them on behalf of the user. If new codec is added, JavaScript would need to be updated to correctly select the parameters for new codec. We should provide a programming model where it is possible to delegate the codec selection and codec parameter negotiation to the RTC API while still allowing to do this negotiation from JavaScript. P.S. I do find the current API proposal a bit deficient due to its inability to support forking, asymmetric codec selection, and delegating codec negotiation to the RTC implementation. _____________ Roman Shpount
- Re: [rtcweb] Making progress on the signaling dis… Cullen Jennings
- Re: [rtcweb] Making progress on the signaling dis… Ted Hardie
- [rtcweb] Making progress on the signaling discuss… Ted Hardie
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Ted Hardie
- Re: [rtcweb] Making progress on the signaling dis… Matthew Kaufman
- Re: [rtcweb] Making progress on the signaling dis… Matthew Kaufman
- Re: [rtcweb] Making progress on the signaling dis… Hadriel Kaplan
- Re: [rtcweb] Making progress on the signaling dis… Ravindran Parthasarathi
- Re: [rtcweb] Making progress on the signaling dis… Magnus Westerlund
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Ted Hardie
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Harald Alvestrand
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Stefan Håkansson LK
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Stefan Håkansson LK
- Re: [rtcweb] Making progress on the signaling dis… Dzonatas Sol
- Re: [rtcweb] Making progress on the signaling dis… Ted Hardie
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Ravindran Parthasarathi
- Re: [rtcweb] Making progress on the signaling dis… Magnus Westerlund
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Harald Alvestrand
- Re: [rtcweb] Making progress on the signaling dis… Neil Stratford
- Re: [rtcweb] Making progress on the signaling dis… Harald Alvestrand
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Harald Alvestrand
- Re: [rtcweb] Making progress on the signaling dis… Matthew Kaufman
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Stefan Håkansson LK
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Harald Alvestrand
- Re: [rtcweb] Making progress on the signaling dis… Neil Stratford
- Re: [rtcweb] Making progress on the signaling dis… Harald Alvestrand
- Re: [rtcweb] Making progress on the signaling dis… Timothy B. Terriberry
- Re: [rtcweb] Making progress on the signaling dis… Tim Panton
- Re: [rtcweb] Making progress on the signaling dis… Roman Shpount
- Re: [rtcweb] Making progress on the signaling dis… Iñaki Baz Castillo
- Re: [rtcweb] Making progress on the signaling dis… Roman Shpount
- Re: [rtcweb] Making progress on the signaling dis… Randell Jesup
- Re: [rtcweb] Making progress on the signaling dis… Randell Jesup
- Re: [rtcweb] Making progress on the signaling dis… Roman Shpount
- Re: [rtcweb] Making progress on the signaling dis… Randell Jesup
- Re: [rtcweb] Making progress on the signaling dis… Roman Shpount
- Re: [rtcweb] Making progress on the signaling dis… Randell Jesup