Hi, all. To support Chris's case I want to offer scenario of multihome gateway (to other than IP network) where media (voice, video or data) processing associated with different network interfaces (and different from the one that is used for signaling). I think this gateway will look the same as Charles' IWF for the observer from the H323 space. But nobody will say that it does third party registration. Best Regards, llya cwp@ISDN-COMMS.CO.UK writes:

All,

Please please PLEASE can we have some more opinions on this important definition, though. Charles and I simply disagree, and a wider pool of opinion is needed in order for consensus to be reached. Although I disagree with Charles's view I am willing to espouse it if that's the way the majority of experts see things. Without further input we'll simply go round in circles.

Charles, All,

I believe the fundamental question about "third-partyness" in this context is what entity or entities will handle the H.225.0/Q.931 and or H.245 signalling. My understanding of the type of IWF you are talking about (at least, the way I would implement such a thing!) is that the IWF terminates all signalling, with RTP data going direct end to end. So it is the entity that is performing the registration that will handle all signalling (namely what you in your SIP-centred way call and IWF and I in my H.323-centred way call a gateway!). To me this is a fair definition of first-party. The only thing the IWF is not terminating is (voice, video and application) data. This does not make the registration third-party in my opinion. There is no assumption (as far as I can remember, anyway) that H.323 entities have to handle their own RTP sessions - they are required only to exchange addresses to terminate these sessions.

Simple question: What is your definition of a "*true* H.323 entity"? In what sense is your gateway/IWF not a "*true* H.323 entity"?

Additive registration is NOT third-party registration by my definition.

Regards, Chris

"Agboh, Charles" wrote:

...

Hi Chris,

I see what you mean. I think you are working under the assumption that the "..other H.323 entities" are *true* H.323 entites. The IWF may give the impression that they are H.323 entities but it doesn't mean they are.

In this model, I am assuming that the "third-party" is receving all signalling from the GK whether it (the GK) is in DRC or GRC mode.

Q: Do I really care if the "..other H.323 entities" are *true* H.323 entities or not? A GK probably couldn't say if the "first-party" being registered (the entitry being registered as apposed to the entity receiving the registration) is a *true* H.323 entity or not. A: It may be usefull. A GK can invoke a special feature if it can differentiate.

H.323v4 defines the additive registration feature, which by your definition is a third-party registration, right? So how does the GK know that the "first-party" is a *true* H.323 entitry?

Best Regards, charles

-----Original Message----- From: Chris Wayman Purvis [mailto:cwp@isdn-comms.co.uk] Sent: Monday, November 27, 2000 6:19 PM To: Agboh, Charles Cc: 'ITU-SG16@mailbag.cps.intel.com' Subject: Re: Third party registration/group registration

Charles,

...

My undstanding of "third-party" registration is the same as yours. But, in some applications a registration by the IWF may not be on its own behalf. These two sentences contradict each other. Please reread my explanation of my understanding, as it is impossible for you to agree with it and believe what you have written in the second sentence above. Unless I misunderstand your definition of an "IWF", which I take to be synonymous with a "gateway" as defined in the H.323 series of standards.

...

H.323v4 provides this feature (a way to bypass the UDP packet size limitation) for this same reason.

Does it make sense to have this?, If no, then why not?

SupportedProtocols ::= CHOICE { nonStandardData NonStandardParameter, h310 H310Caps, h320 H320Caps, h321 H321Caps, h322 H322Caps, h323 H323Caps, h324 H324Caps, voice ......., SIP SIPCaps } This may make sense (and is what I meant when I referred to "supportedPrefixes"). If this is a way forward that you believe would be useful for SIP gateways I would encourage you to write a formal proposal to an ITU SG16 experts meeting on this basis.

Regards, Chris

...

-----Original Message----- From: Chris Wayman Purvis [mailto:cwp@isdn-comms.co.uk] Sent: Monday, November 27, 2000 10:41 AM To: Agboh, Charles Cc: ITU-SG16@mailbag.cps.intel.com Subject: Re: Third party registration/group registration

Charles,

Wrong in my opinion, but I would hope other experts would express their opinions too! The problem is I'm not sure whether this is a question of understanding or of detailed definition of the phrase "third party" in this context. My understanding of the phrase "third party registration" would be one H.323 entity registering at a gatekeeper on behalf of other H.323 entities. My understanding of the word "registration" of this context is that it can only apply to H.323 entities. In this context the IWF can be considered to be at the extreme edge of the H.323 network, so any "registration" it does is on its own behalf. Maybe what you actually want is some equivalent to the supportedPrefixes that arrived in version 2, for SIP gateways. Whatever we agree you want, though, I think it is worth trying to reach some consensus among experts in this group as to what the phrase "third party" means in this context - as your understanding and mine are clearly in disagreement.

Regards, Chris

"Agboh, Charles" wrote:

...

Chris,

There are applications where an IWF can register an EP from one domain

into

...

another. This allows automatic visibility of EP from one domain from another. In this case the IWF is registering not only itself but other EPs. For this scenario, the third-party entity is the IWF, right?

regards,

charles -- Dr Chris Purvis -- Development Manager ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road Winkfield Row, Berkshire. RG42 6LY ENGLAND Phone: +44 1344 899 007 Fax: +44 1344 899 001

-- Dr Chris Purvis -- Development Manager ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road Winkfield Row, Berkshire. RG42 6LY ENGLAND Phone: +44 1344 899 007 Fax: +44 1344 899 001

-- Dr Chris Purvis -- Development Manager ISDN Communications Ltd, The Stable Block, Ronans, Chavey Down Road Winkfield Row, Berkshire. RG42 6LY ENGLAND Phone: +44 1344 899 007 Fax: +44 1344 899 001

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