[AG-TECH] H.323 / Mbone Gateway Progress?

Ivan R. Judson judson at mcs.anl.gov
Thu May 23 12:47:23 CDT 2002

Hi Mike,

One method we've discussed of solving this problem, since it "feels"
technically, architecturally, and socially good is to augment the
OpenMCU software available as part of the Open H.323 Project

The technical challenges to this include:

1) Mixing the venue audio into a single stream and transcoding it from
16KHz to 8KHz to send to H.323 participants
2) transcoding audio from the H.323 participants from 8KHz to 16KHz
3) Building some mechanism for time-switching, voice-switching, tiling,
or otherwise selecting a single video stream to be sent to the H.323

Other than these more difficult issues, it looks to me like the OpenMCU
has a lot of the mechanisms internally to do this very elegantly.  If
anyone is interested in this project, please contact me and I'll help
try and get things going.  This has been a hot topic for a long time and
really needs to be addressed.


-----Original Message-----
From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On
Behalf Of Mike Daw
Sent: Thursday, May 23, 2002 11:07 AM
To: AG Technical Developers (E-mail)
Cc: David Boyd (E-mail)
Subject: [AG-TECH] H.323 / Mbone Gateway Progress?

I am trying to anticipate an issue that might be raised in the UK in the
near future. This issue is that many companies have invested extensively
in H.323 videoconferencing solutions and that the UK Govt. is beginning
to invest widely in the AG solution in academia through the e-Science
programme (12 nodes currently, more coming soon).

So, the obvious question is, when will we be able to have a meeting from
our AG node to someone's videoconferencing facility (forget about the
desirability of this for the moment)?

I've just spent a pleasant couple of hours reading a fascinating
document I found on the web about a meeting attended (among others) by
our very own Terry Disz, Bill Nickless and Bob Olson. This document
outlines a lot of the technological issues as well as the desirability
angle, given what the AG is trying to achieve. It's here, if anyone's

However, the discussion happened 18 months ago. Its conclusions talk
about conducting a survey, looking into the shape of a possible
H.323/Mbone gateway and thinking about funding for development work into
this gateway.

Can anyone tell me whether anything is happening or is planned to happen
on this? What's gone on in the intervening 18 months?

Michael Daw
Computer Services for Academic Research (CSAR)

Manchester Computing, Kilburn Building,
University of Manchester, Manchester M13 9PL, UK

Tel: +44 (0)161 275 7026
Fax: +44 (0)161 275 6800
Email: michael.daw at man.ac.uk


More information about the ag-tech mailing list