Subject: Re: FYI: new ID draft-bouwen-megaco-isdn-00.txt

From: "Petros N. Mouchtaris" <[email-masked]>
Date: Wed, 15 Mar 2000 11:22:01 -0500

Matt,

Let me make sure I understand what you are saying:
draft-bouwen-megaco-isdn-00.txt identifies three ISDN backhaul mechanisms:
1) Translate Q.931 messages into Megaco/H.248 events and signals
2) Embed Q.931 messages in MEGACO/H.248 as MIME attachements
3) Use IUA over SCTP

You are proposing to extend option 3 to include TCP instead of SCTP and
eliminate options 1 and 2.
I tend to agree that option 3 is probably the most viable choice.

Petros

Matt Holdrege <[email-masked]> on 03/15/2000 09:01:47 AM

Please respond to Matt Holdrege <[email-masked]>

To:   [email-masked]
cc:    (bcc: Petros N. Mouchtaris/Telcordia)
Subject:  Re: FYI: new ID draft-bouwen-megaco-isdn-00.txt

I spoke to Jan today and I ought to fill in everyone else. First of all, at
the last design team conference call I was able to finally express verbally
my reasons for putting a TCP option into the UA's. We agreed to put a small
note about TCP in the introduction with a pointer to a TCP section later in
the documents. The bottom line is that SCTP is the main transport for the
UA's, but TCP is a viable option in *certain* scenarios. You'll all be able
to review this text in the rev's following Adelaide.

So with the ability to do TCP and the seemingly best choice of the SIGTRAN
IUA to transport many of us are recommending against ISDN backhaul with
MEGACO. It's obviously better to have one choice in this case.

At 09:42 AM 3/14/00 +0100, Bart Van Doorselaer wrote:
>"Issues for Megaco - Sigtran Interworking in ISDN Access Gateways ", Jan
>Bouwen, Bart Van Doorselaer, Miek Dekeyser, 03/13/2000. (71198 bytes)
>
>http://www.ietf.org/internet-drafts/draft-bouwen-megaco-isdn-00.txt
>
>This document introduces the concept of an ISDN access gateway in the
>context of Megaco/H.248 and Sigtran protocols. For these ISDN access
>gateways, the ISDN B channels may be controlled by the Media Gateway
>Controller using megaco/H.248 while the User-to-Network signaling
>running over the D channels may be relayed to the Media Gateway
>Controller using either megaco/H.248 or the Sigtran protocols. The main
>issues involved are:
>* Megaco/H.248 and Sigtran protocols may interwork in different ways in
>ISDN access gateways, leaving room for non - interoperable solutions;
>* Megaco needs additional packages in order to support ISDN terminations
>in the ISDN access gateway;
>* A data service may be offered to ISDN users via the ISDN D- channel,
>introducing the need to introduce a NAS package for the D-channel.
>This document addresses these issues, proposes and explains different
>solutions and suggests best practice guideline for megaco / sigtran
>interworking in ISDN access gateways.
>
>
>Enjoy the reading.
>
>
>--
>                                               ____________________
>Bart Van Doorselaer                           \                  /
>_______________________________________________\                /____
>                                                 \              /
>Research Engineer                                \  ALCATEL   /
>DN2                                          Network Strategy Group
>Tel   : +32 3 240 86 41                      Francis Wellesplein  1
>Fax   : +32 3 240 99 32                     B-2018 Antwerpen Belgium
>_____________________________________________________\    /__________
>mailto:[email-masked]                 \  /
>                                                        \/

---

From: Matt Holdrege <[email-masked]>
Date: Wed, 15 Mar 2000 23:46:10 -0800

Petros, you understand me correctly. Except that I do not say to use TCP
instead of SCTP. Rather TCP is an option in certain scenarios. According to
SIGTRAN agreements, implementations may use either TCP or SCTP.