Re: [pntaw] Real-time media over TCP

Harald Alvestrand <harald@alvestrand.no> Mon, 02 September 2013 08:36 UTC

Return-Path: <harald@alvestrand.no>
X-Original-To: pntaw@ietfa.amsl.com
Delivered-To: pntaw@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id CE58511E81D4 for <pntaw@ietfa.amsl.com>; Mon, 2 Sep 2013 01:36:20 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -110.532
X-Spam-Level:
X-Spam-Status: No, score=-110.532 tagged_above=-999 required=5 tests=[AWL=0.067, BAYES_00=-2.599, RCVD_IN_DNSWL_HI=-8, USER_IN_WHITELIST=-100]
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 XZ0m977f+XZZ for <pntaw@ietfa.amsl.com>; Mon, 2 Sep 2013 01:36:14 -0700 (PDT)
Received: from eikenes.alvestrand.no (eikenes.alvestrand.no [158.38.152.233]) by ietfa.amsl.com (Postfix) with ESMTP id 0B1DC11E8125 for <pntaw@ietf.org>; Mon, 2 Sep 2013 01:35:41 -0700 (PDT)
Received: from localhost (localhost [127.0.0.1]) by eikenes.alvestrand.no (Postfix) with ESMTP id ABC0D39E0F0 for <pntaw@ietf.org>; Mon, 2 Sep 2013 10:35:36 +0200 (CEST)
X-Virus-Scanned: Debian amavisd-new at eikenes.alvestrand.no
Received: from eikenes.alvestrand.no ([127.0.0.1]) by localhost (eikenes.alvestrand.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AODXKMACxI63 for <pntaw@ietf.org>; Mon, 2 Sep 2013 10:35:36 +0200 (CEST)
Received: from hta-hippo.lul.corp.google.com (unknown [IPv6:2620:0:1043:1:7646:a0ff:fe90:e2bb]) by eikenes.alvestrand.no (Postfix) with ESMTPSA id 114E339E091 for <pntaw@ietf.org>; Mon, 2 Sep 2013 10:35:36 +0200 (CEST)
Message-ID: <52244DD7.1020900@alvestrand.no>
Date: Mon, 02 Sep 2013 10:35:35 +0200
From: Harald Alvestrand <harald@alvestrand.no>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130804 Thunderbird/17.0.8
MIME-Version: 1.0
To: pntaw@ietf.org
References: <CAGTXFp92jSzQz05uHngzscz88n=fT_JPbEvQRxgeUUqPVRQUyQ@mail.gmail.com>
In-Reply-To: <CAGTXFp92jSzQz05uHngzscz88n=fT_JPbEvQRxgeUUqPVRQUyQ@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [pntaw] Real-time media over TCP
X-BeenThere: pntaw@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: "Discussion list for practices related to proxies, NATs, TURN, and WebRTC" <pntaw.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/pntaw>, <mailto:pntaw-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/pntaw>
List-Post: <mailto:pntaw@ietf.org>
List-Help: <mailto:pntaw-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/pntaw>, <mailto:pntaw-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 02 Sep 2013 08:36:22 -0000

On 08/30/2013 12:12 PM, Victor Pascual Avila wrote:
> Hi,
>
> Real-time media over TCP has some inherent challenges -- is this
> something we're planning to discuss here? We did RTP over TCP (+ HTTP
> CONNECT) in the past and ended up using multiple connections along
> with application-layer redundancy. I'm wondering whether we'll be able
> to do the same when moving to WebRTC

If you really want to go there, I suggest you take a good hard look at 
either SCTP or TCP Minion (draft-iyengar-minion-concept-01.txt).

The RTCWeb stack already uses SCTP over DTLS over UDP.

In either case, I don't think performance of RTP over reliable transport 
is a firewall-related issue.