Radhika,
Yes, AT&T's contribution, like other proposals, also separates between
the
RAS signaling stage and the call signaling stage. So, the call signaling
is
free to take any path as appropriate.
Thank you for this clarification. Given that you are now permitting call-signalling and RAS messages to follow different routes I see no advantage, when placing a call between administrative domains, to routing any RAS message other than LRQ/LCF/LRJ between gatekeepers/BEs.
The other problem your proposal appears to be trying to solve appears to be that of roaming users. Andrew Draper's email of 21st August explains why there is no necessity for a roaming endpoint to register with a foreign gatekeeper. Thus support of roaming users is no reason to route GRQ/GCF/GRJ, RRQ/RCF/RRJ, ARQ/ACF/ARJ, BRQ/BCF/BRJ, URQ/UCF/URJ, DRQ/DCF/DRQ, IRQ/IRR/IACK/INACK and RAI/RAC/RIP/NSM/XRS between gatekeepers.
Nokia's APC 1382 (S. Sengodan, Nokia, "On the Use of Multicast Scope for Gatekeeper Discovery," is explicitly limited to GRQ/GCF/GRJ, and may be of interest as a way of propogating knowledge of gatekeepers within an administrative domain. The zone messages proposed by Jim Toga in APC-1422 are an alternative solution to a similar problem.
Regards, Chris -- Dr Chris Purvis - Senior Development Engineer, WAVE CC Software Madge Networks Ltd, Wexham Springs, Framewood Road, Wexham, Berks. Phone:+44 1753 661359 email: cpurvis@madge.com