As far as H.323 is concerned, all endpoints are H.323 endpoints. They are further sub-qualified as either "terminals" or "gateways".
The line becomes a little blurr when the physical device we are thinking of is a telephone set behind some sort of IP PBX or Gateway. That telephone can even be an H.248-controlled device. You could view the "proxy" as either a Gateway, an MCU or a terminal, or even a combination of 2 or 3 of them depending on your personnal preferences. Then there are glitches in the actual H.245 capabilities to negotiate what these entities can support (I think we sorted that out for v4).
In any case, in H.323 terminology, the "endpoint" is the entity that will register aliases with the gatekeeper. This alias can be completely abstract (in which case the numbering plan and mapping to phone numbers themselves would be provisionned in the gatekeeper), or it can be actual phone numbers. H.323v4 even allows for registering large ranges of numbers without explicitly enumerating them (this is useful when you prefer to have the numbering plan managed in each gateways as opposed to a cental gatekeeper).
In the H.323 world, this is not really "third-party" registration since the H.323 proxy is viewed as the first party (the fact that the media will be on different devices is irrelevant). That being said, I would imagine that the same mechanism could be used to register 3rd parties (real H.323 endpoints).
In my opinion, I think all possible angles are covered in H.323v4... I wouldn't like to have even more ways to do registration. If anything, we should probably look into describing a little better how this is supposed to work to facilitate interworking with gatekeepers. We did a little bit in v4 (for example on the use of so-called prefixes, E.164 numbers, and private ISO/IEC 11571 addresses).
My 2 cents...
---- François AUDET, Nortel Networks mailto:audet@nortelnetworks.com mailto:audet@nortelnetworks.com , tel:+1 408 495 3756
-----Original Message----- From: Taylor, Tom-PT [NORSE:B901:EXCH] Sent: Wednesday, November 29, 2000 10:39 AM To: ITU-SG16@MAILBAG.INTEL.COM Subject: Re: Third party registration/group registration
Accurate terminology is obviously useful, but in this case, at least, it looks like something people can agree on and then move on. The more important point seems to be the underlying distinction in requirements:
-- register on behalf of H.323 endpoints -- register on behalf of other endpoints where I use "other" in the sense that the contact address is associated with a non-H.323 signalling protocol. Purity is beside the point here -- it's the intention of the contact address that matters. Stating the requirement in this way makes it obvious that the second requirement includes the need to state which protocol the endpoints expects to receive.
There is another possibility, of course: use the same mechanism to satisfy all requirements, and allow for the possibility that the endpoint supports multiple protocols. I think the design would be cleaner if we took the approach: one contact point, one protocol -- even if it meant repeating the contact information for each protocol a multiprotocol endpoint supports.