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.
> -----Original Message-----
> From: Chris Wayman Purvis [mailto:cwp@ISDN-COMMS.CO.UK]
> Sent: Wednesday, November 29, 2000 4:45 AM
> To: ITU-SG16@MAILBAG.INTEL.COM
> Subject: Re: Third party registration/group registration
>
>
> Charles,
>
> > The IWF (SIP-H.323 gateway) may terminate data (voice,
> video, data) if it
> > determines that the call cannot go from end-to-end. An
> entity outside of
> > the IWF may perform this function on behalf of the IWF. In
> this case, this
> > entity would be under the influence of the IWF.
> Right. But my point is that for a registration is to be
> called "third-party",
> the IWF would have NO part in the proceedings other than the
> registration
> stage. You appear to be ignoring my point about what entity
> is handling
> H.225.0/Q.931 and/or H.245 signalling, which I feel is the
> crucial part of what
> would make a registration "third-party".
>
> > By *true* H.323 entities, I meant an entity that *speaks*
> ONLY H.323. The
> > IWF represents non-H.323 entities on the H.323 network.
> Your "*true*" H.323 entity is an unusual beast indeed, given
> that the majority
> of H.323 devices around are either gateways (speaking another
> protocol) or
> PC-based (in which they generally "*speak*" large varieties
> of protocols for
> different purposes. In fact you restrict your definition of
> "*true*" H.323
> entities to standalone IP phones. The fact that a device
> supports protocols
> other than H.323 does NOT make it any the less a "*true*"
> H.323 device in any
> reasonable definition of the word "true".
>
> > You are right, additive registration is NOT third-party
> registration. Can
> > it be used as a means to achieve scalable third-party registration?
> Additive registrations can, I believe, be used to achieve
> what you are trying
> to achieve. I don't believe it can be used to achieve what
> _I_ understand as
> third-party registration. Our disagreement is around the
> definition of the
> term "third-party registration", the difference in our
> definitions causing
> confusion.
>
> I'll stick my neck out here and say that so far I believe
> consensus is with my
> definition (third-party registration as one H.323 entity
> registering on behalf
> of other entities which are H.323 except in their inability
> or unwillingness to
> register themselves with a gatekeeper) rather than yours (a
> gateway registering
> any device using any protocol with an H.323 gatekeeper). I
> will then promptly
> duck as I wait for the flack to fly!
>
> Regards,
> Chris
> > -----Original Message-----
> > From: Chris Wayman Purvis [mailto:cwp@isdn-comms.co.uk]
> > Sent: Tuesday, November 28, 2000 10:36 AM
> > To: Agboh, Charles; 'ITU-SG16@mailbag.cps.intel.com'
> > Subject: Re: Third party registration/group registration
> >
> > 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
> >
> >
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > For help on this mail list, send "HELP ITU-SG16" in a message to
> > listserv@mailbag.intel.com
>
> --
> 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
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> For help on this mail list, send "HELP ITU-SG16" in a message to
> listserv@mailbag.intel.com
>