The IP over ATM Mailing List Archive by date

[jdd@arl.wustl.edu (John DeHart)]

This thread seems to have quieted, but let me throw in my
two cents worth.

> From: jed@llnl.gov (James E. [Jed] Donnelley)
> Subject: Re: Multicasting with ATM - a concern -> meta (long)
> 
> My conclusion from the discussion on this thread is that
> ATM will not effectively support multipoint to multipoint
> "circuits."  It won't even effectively support bi-directional
> point to multipoint "circuits."  I hope my terminology is
> clear here.  The basic problem is the multiplexing of
> a single circuit data structure while still separating the
> multiple transmitters at the destination - e.g. with VCIs
> within a VPI or whatever.

There doesn't seem to be any reason why ATM can not effectively support
multipoint to multipoint circuits. A lot of ATM switching hardware
supports it today. It is not difficult to build a call model and signaling
structures that support it. 

I think given the capapbility to use mpt-to-mpt you would find an explosion
of applications and services that would use it. Virtual Environments have
already been mentioned. General conferencing applications are another
For these applications to scale it seems that a flexible, efficient
general multipoint paradigm is needed. The signaling and control operations
needed to scale an overlay of N  1xM connections blows up as you try to 
add new participants.

There are still probably significant issues to address in the areas
of traffic management in general multipoint connections.

Here are some pointers to some papers concerning general multipoint call models
and signaling:
http://www.arl.wustl.edu/~jdd/Papers

John DeHart
jdd@arl.wustl.edu