Oops! Sorry about the blank response! Let's try again!
This isn't QUITE as simple a question as it looks. I'd recommend looking at it from the two separate points of view:
From the endpoint's point of view, I would say the answer is "yes" (as Ritu
says). A gatekeeper is allowed to send you a DRQ to clear the call. Depending on how the endpoint is written, though, this may not be trivial to achieve, since without pregranted ARQs it is reasonable for an endpoint to want to match up DRQs with individual ARQs.
As a gatekeeper, though, I wonder why one would want to implement that. For the gatekeeper to be aware of a call when using pregranted ARQs, it must be routing call signalling, so it can quite happily terminate the call by means of ReleaseComplete - which will NOT break poorly written endpoints.
The related question is whether an endpoint sends a DRQ on "normal" call termination in these cases. If the gatekeeper is routing call-signalling it is arguably unnecessary (ReleaseComplete clears the call); if not, then potentially the first the gatekeeper knows about the call is the DRQ at its end (not useful!)! Note that H.323v2 section 8.5.2 assumes that ARQ has happened at the beginning of the call, so behaviour where this is absent (due to pregranted ARQ) is arguable.
This leaves a question mark over the use of the other call-specific RAS message, BRQ. Bandwidth issues with pregranted ARQs are discussed in both a contribution and a TD from the recent Monterey meeting (I forget the numbers).
Regards, Chris -- Dr Chris Purvis - Senior Development Engineer, WAVE CC Software Madge Networks Ltd, Wexham Springs, Framewood Road, Wexham, Berks. ENGLAND Phone: +44 1753 661 359 email: cpurvis@madge.com
-----Original Message----- From: rtgupta@hss.hns.com [mailto:rtgupta@hss.hns.com] Sent: 09 March 1999 5:19 To: srini@trillium.com Cc: h323implementors@imtc.org; ITU-SG16@mailbag.cps.intel.com Subject: Re: call clearing by GK
Hi srini, Gatekeeper can clear an ongoing call by sending DRQ to an endpoint. Refer to section 8.5.3, ITU-T H.323 recommendation.
Thanks, Ritu. _____________________________________________________________________ Ritu Gupta | email: rtgupta@hss.hns.com Senior Software Engineer, | rtgupta@hotmail.com Hughes Software Systems, | phone: 91-80-2286390/91/92(W) Banglore, Karnataka | 91-80-3374075(H) INDIA. | Fax : 91-80-2286393 _____________________________________________________________________ Restlessness and discontent are the first necessities of progress.
srini@trillium.com (Srinivasa Beereddy) on 03/09/99 05:29:43 AM
Please respond to srini@trillium.com (Srinivasa Beereddy)
To: h323implementors@imtc.org, ITU-SG16@mailbag.cps.intel.com cc: Subject: call clearing by GK
I have a question on call clearing by Gatekeeper. Can a GateKeeper send DRQ to clear the call in a preGrantedArq case? thanks in advance. Srini Trillium Digital Systems, Inc.