IETF Logo Mail Archive

Re: [rtcweb] Sending of zero-length messages over data channels

Michael Tuexen <Michael.Tuexen@lurchi.franken.de> Wed, 23 July 2014 11:12 UTC

Return-Path: <Michael.Tuexen@lurchi.franken.de>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 70C471A02EC for <rtcweb@ietfa.amsl.com>; Wed, 23 Jul 2014 04:12:13 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.552
X-Spam-Level:
X-Spam-Status: No, score=-1.552 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, HELO_EQ_DE=0.35, RP_MATCHES_RCVD=-0.001, SPF_HELO_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 CSlIpLOz83Ry for <rtcweb@ietfa.amsl.com>; Wed, 23 Jul 2014 04:12:11 -0700 (PDT)
Received: from mail-n.franken.de (drew.ipv6.franken.de [IPv6:2001:638:a02:a001:20e:cff:fe4a:feaa]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 73F9C1A02DD for <rtcweb@ietf.org>; Wed, 23 Jul 2014 04:12:11 -0700 (PDT)
Received: from dhcp-9132.meeting.ietf.org (dhcp-9132.meeting.ietf.org [31.133.145.50]) (Authenticated sender: macmic) by mail-n.franken.de (Postfix) with ESMTP id 0A38C1C104DEA; Wed, 23 Jul 2014 13:12:07 +0200 (CEST)
Content-Type: text/plain; charset="us-ascii"
Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\))
From: Michael Tuexen <Michael.Tuexen@lurchi.franken.de>
In-Reply-To: <CAOJ7v-0F9pysYLehjTVDv1Sxz3TKaxi2y6J7RrpGqMdA=tiR_g@mail.gmail.com>
Date: Wed, 23 Jul 2014 07:12:06 -0400
Content-Transfer-Encoding: quoted-printable
Message-Id: <2CB7681C-815F-48BD-8BC0-A1F13ED6A9F5@lurchi.franken.de>
References: <CAOJ7v-0F9pysYLehjTVDv1Sxz3TKaxi2y6J7RrpGqMdA=tiR_g@mail.gmail.com>
To: Justin Uberti <juberti@google.com>
X-Mailer: Apple Mail (2.1878.6)
Archived-At: http://mailarchive.ietf.org/arch/msg/rtcweb/COu7m7Ep5fC3y6bh3tv2MrgDJP0
Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] Sending of zero-length messages over data channels
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.15
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, 23 Jul 2014 11:12:13 -0000

On 22 Jul 2014, at 23:58, Justin Uberti <juberti@google.com> wrote:

> In the existing data channel protocol, it's not possible to send zero-length messages, because SCTP prohibits it.
> 
> While this may seem to be an academic point, it does represent a divergence from WebSockets, and this difference could be meaningful to applications who use empty messages for keepalives. Or maybe the Yo app.
> 
> Since we can't send a zero-length SCTP message, I propose we add a PPID_EMPTY value or something similar to indicate a message with empty content.
That works. The corresponding payload would be ignored...
One could add a sentence or two in
http://tools.ietf.org/html/draft-ietf-rtcweb-data-channel-11#section-6.6
and in the IANA section.

Best regards
Michael
> _______________________________________________
> rtcweb mailing list
> rtcweb@ietf.org
> https://www.ietf.org/mailman/listinfo/rtcweb

v2.23.0 | Report a Bug | By Email