Subject: Re: H.248/BICC discussions

From: Sophia Scoggins <[email-masked]>
Date: Fri, 2 Jun 2000 12:00:42 -0400

It would be better that we have just one cohesive coding mechanism to
carry information end-to-end for all MGCs and MGs.

There are indeed too many parameters in the Annex C. I am not sure if
many of them will ever be used. Somewhere I heard or saw that the
average length of SDP messages is only 60 bytes. How much of info do we
really want to carry in the SDP? Many of the Q.9XX parameters need not
to carry through the path MG --> MGC --> MGC --> MG. ISUP trunks would
be choking by large packets -- SIP has less issues with big packets.

However, in Nortel's contribution to SG11, we have identified two
parameters that are needed but not included in the Annex C:

-- eecid or bnc-id (this is included in Rajesh Kumar's ATM SDP)
-- use RTCP or not (RTCP is optional to RTP. We need to specify to use
RTCP or not.)

Regards, SOphia

---

From: Christian Groves <[email-masked]>
Date: Mon, 5 Jun 2000 13:49:28 +1000

Hello Sophia,

BNC-ID is included in Annex C - see table 3 BIR - Binding Reference.
Use RTCP or not could be added as an extension to the RTP Package.

Whilst using SDP as the cohesive glue in MGC-MG architectures is
admirable MG to MG parameters are typically used as a mechanism to set
up a bearer/connection. There are other protocols today to do this work
so I suspect that when adding parameters to SDP you'll have a superset a
properties not used by all applications, as per Annex C. The challenge
will be to define to one's you want in a certain scenario so that every
can interoperate. In H.248 it will be a package and optionally a
profile.

Regards, Christian