IETF Logo Mail Archive

Re: DTMF signaling between media gateways - ouch!

Colin Perkins <c.perkins@cs.ucl.ac.uk> Sun, 14 November 1999 08:49 UTC

Received: from lists.research.bell-labs.com (paperless.dnrc.bell-labs.com [135.180.161.172]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id DAA17494 for <sip-archive@odin.ietf.org>; Sun, 14 Nov 1999 03:49:04 -0500 (EST)
Received: by lists.research.bell-labs.com (Postfix) id 1C81D530D; Sun, 14 Nov 1999 03:45:47 -0500 (EST)
Delivered-To: sip-outgoing-local@paperless.dnrc.bell-labs.com
Received: by lists.research.bell-labs.com (Postfix, from userid 20006) id 6E4245310; Sun, 14 Nov 1999 03:45:46 -0500 (EST)
Delivered-To: sip-local@paperless.dnrc.bell-labs.com
Received: from scummy.research.bell-labs.com (research.research.bell-labs.com [135.104.2.10]) by lists.research.bell-labs.com (Postfix) with SMTP id 95996530D for <sip@lists.research.bell-labs.com>; Sun, 14 Nov 1999 03:45:05 -0500 (EST)
Received: from dusty.research.bell-labs.com ([135.104.2.7]) by scummy; Sun Nov 14 03:44:21 EST 1999
Received: from bells.cs.ucl.ac.uk ([128.16.5.31]) by dusty; Sun Nov 14 03:43:13 EST 1999
Received: from cperkins-d.cs.ucl.ac.uk by bells.cs.ucl.ac.uk with local SMTP id <g.04509-0@bells.cs.ucl.ac.uk>; Sun, 14 Nov 1999 08:44:03 +0000
Received: from cperkins-d.cs.ucl.ac.uk (localhost [127.0.0.1]) by cperkins-d.cs.ucl.ac.uk (8.9.3/8.8.7) with ESMTP id SAA10154; Sat, 13 Nov 1999 18:06:46 GMT
Message-Id: <199911131806.SAA10154@cperkins-d.cs.ucl.ac.uk>
To: "Gregory D. Girard" <ggirard@mediaone.net>
Cc: Dean Willis <dean.willis@wcom.com>, "Dye, Robert" <rdye@sonusnet.com>, sip <sip@lists.research.bell-labs.com>
Subject: Re: DTMF signaling between media gateways - ouch!
In-Reply-To: Message from "Gregory D. Girard" <ggirard@mediaone.net> of "Fri, 12 Nov 1999 08:26:35 EST." <016401bf2d11$8ad2fbc0$122cda18@goliath.ne.mediaone.net>
Date: Sat, 13 Nov 1999 18:06:46 +0000
From: Colin Perkins <c.perkins@cs.ucl.ac.uk>
Sender: owner-sip@lists.research.bell-labs.com
Precedence: bulk

--> "Gregory D. Girard" writes:
>Aside from other considerations, in my opinion, any DTMF signalling
>technique that RELIES upon an IP transport (RTP in this case) is dead on
>arrival. Such an approach pre-supposes the bearer channel transport
>technology and thus binds SIP to VoIP solutions. Insofar as ATM and Frame
>Relay transports exist (and particularly ATM, which is coming on strong)
>and are growing, it makes no sense to me to create an artificial
>dependency on IP/RTP.

To clarify, whilst most RTP implementations use UDP/IP as their transport,
the protocol was intentionally defined to be transport neutral and does not
mandate IP.

Colin

v2.41.0 | Report a Bug | By Email | System Status