Subject: [AVTCORE] Knowing when to use RFC 2190 vs. RFC 2429/4629 for H.263 video?

From: Max Magliaro <[email-masked]>
Date: Thu, 7 Jul 2011 15:38:23 -0700

RFC 2429 is the preferred format (actually  4629 now).
However, 2190 may still have to be used for some legacy systems.

If I am one of those legacy endpoints,  (and I am)
what, in the H.245 call signalling of an H.323 call, do I use to indicate
to the other end NOT to send me the newer-style payload header?

Specifically, I note that when I call to a Polycom RMX system, it 
exchanges H.263 with me
just fine.   However, if it opens a secondary H.239 collaboration video 
channel,
it sends that one with the newer-style headers.   When I call a Tandberg 
system,
this doesn't happen (they send 2190 style headers in the collaboration 
channel and everything
works).  If I try this with a Polycom VSX, it doesn't do this (all works 
fine).

I assume there is some "hint" in my capability set that I need to set, 
or avoid setting, so
that all endpoints (including Polycom's RMX) will know to not send the 
newer-style headers.
Or maybe it's the opposite, that there is something in the capabilities 
I need to
NOT set.

I realize that the ideal solution would be to support the current header 
structure, but I do not
have that option available to me.

If anyone has a hint as to how Polycom makes that decision to send RFC 
2190 or RFC 2429/4629,
I would appreciate it.

Thank you,

Max Magliaro
Broadband Networks, Inc