Radhika, Gary, H.323v2, section 6.7: "The MCU is an endpoint which provides support for multipoint conferences. The MCU shall consist of an MC and zero or more MPs." Note that the phrase used is "consist of", not "contain". If an MCU is an endpoint, it is callable (I think we're agreed on that). If it consists of an MC and zero or more MPs, that means it must still be callable when it consists of only an MC. Therefore the MC is the part of an MCU that is callable. Hence an MC MAY be a callable entity. The wider point is that my understanding was that all control signalling done by an MCU was done by the MC part of it (again on the basis of those two sentences). If this is inconsistent with other parts of the standard, then it certainly needs to be fixed (please give references); if it is consistent with the rest of the standard, but not what was intended, then we need to reconsider what we really want. For the case under discussion I'd agree with Gary that it's a minor semantic quibble (and as such I was planning to allow Gary's mail on its own to pass without comment), but if there's the possibility of it becoming more than that maybe we ought to clear it up. Regards, Chris
-----Original Message----- From: Roy, Radhika R, ALCOO [mailto:rrroy@ATT.COM] Sent: 05 March 1999 2:08 To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Invitation via Gatekeeper
This was my understanding as well.
Does anyone disagree with Gary?
Regards, Radhika
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Radhika R. Roy AT&T Labs Room C1-2B03 200 Laurel Avenue S. Middletwon, NJ 07748 USA + 1 732 420 1580 Tel rrroy@att.com
-----Original Message----- From: Gary A. Thom [SMTP:gthom@DELTA-INFO.COM] Sent: Friday, March 05, 1999 11:18 AM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Invitation via Gatekeeper
I have this minor semantic clarification:
2. I disagree with Linh's assertion that "an MC never sends ARQ". If I am administering an MCU which can initiate conferences by calling up a list of participants at a given time, I will certainly require that MCU to apply to its gatekeeper for permission to make these calls. In the particular case under discussion, E2/its MC certainly has to send ARQ. It is going to make a call, which will result in data flowing its gatekeeper's zone, and which may end up costing money.
The original idea was that only endpoints send ARQ. An MC is not an endpoint, however, it is a functional element which can be contained in an endpoint (such is the case of an MCU or a terminal which contains an MC). So even though the endpoint contains an MC, it is the endpoint which is sending the ARQ not the MC functional element.
If an MC exists in the Gatekeeper, I do not beleive that that MC will ever send ARQ for any of the connections in the conference. Only the endpoints in that conference will send ARQ to their Gatekeepers.
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