[rtcweb] Symmetric RTP and uni-directional media streams

Christer Holmberg <christer.holmberg@ericsson.com> Thu, 01 September 2011 11:21 UTC

Return-Path: <christer.holmberg@ericsson.com>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (localhost []) by ietfa.amsl.com (Postfix) with ESMTP id 2B4B521F85F2 for <rtcweb@ietfa.amsl.com>; Thu, 1 Sep 2011 04:21:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.528
X-Spam-Status: No, score=-6.528 tagged_above=-999 required=5 tests=[AWL=0.070, BAYES_00=-2.599, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([]) by localhost (ietfa.amsl.com []) (amavisd-new, port 10024) with ESMTP id scPE01yShkLA for <rtcweb@ietfa.amsl.com>; Thu, 1 Sep 2011 04:21:39 -0700 (PDT)
Received: from mailgw10.se.ericsson.net (mailgw10.se.ericsson.net []) by ietfa.amsl.com (Postfix) with ESMTP id 0431021F85F1 for <rtcweb@ietf.org>; Thu, 1 Sep 2011 04:21:38 -0700 (PDT)
X-AuditID: c1b4fb3d-b7c47ae000000b17-12-4e5f6b1d8fbe
Received: from esessmw0237.eemea.ericsson.se (Unknown_Domain []) by mailgw10.se.ericsson.net (Symantec Mail Security) with SMTP id AE.48.02839.D1B6F5E4; Thu, 1 Sep 2011 13:23:09 +0200 (CEST)
Received: from ESESSCMS0356.eemea.ericsson.se ([]) by esessmw0237.eemea.ericsson.se ([]) with mapi; Thu, 1 Sep 2011 13:23:08 +0200
From: Christer Holmberg <christer.holmberg@ericsson.com>
To: "rtcweb@ietf.org" <rtcweb@ietf.org>
Date: Thu, 01 Sep 2011 13:23:06 +0200
Thread-Topic: Symmetric RTP and uni-directional media streams
Thread-Index: AcxomYV8muHlGwn7Tpe2Zvqda7t9+A==
Message-ID: <7F2072F1E0DE894DA4B517B93C6A05852233DD0AC8@ESESSCMS0356.eemea.ericsson.se>
Accept-Language: en-US
Content-Language: en-US
acceptlanguage: en-US
Content-Type: multipart/alternative; boundary="_000_7F2072F1E0DE894DA4B517B93C6A05852233DD0AC8ESESSCMS0356e_"
MIME-Version: 1.0
X-Brightmail-Tracker: AAAAAA==
Subject: [rtcweb] Symmetric RTP and uni-directional media streams
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: Thu, 01 Sep 2011 11:21:40 -0000


There has been much talk about the usage of symmetric RTP. Also, draft-perkins-rtcweb-rtp-usage suggests that symmetric RTP is required.

However, the PeerConnection API currently only supports the establishment of uni-directional streams, so for a single two way communication one needs to create two separate uni-directional streams.

So, I assume that one requirement from RTCWEB to W3C will be to add support of the establishment of bi-directional streams to the PeerConnection API.