[H.323 Mobility:] questions on MTD-016

Stephen Terrill stephen.terrill at ERICSSON.COM
Thu Apr 13 11:22:00 EDT 2000


Hi Jaakko,

>From what you have written, do I understand that you view that for a terminating call (incomming), the call won´t be routed via the home network - regardless of where the services are being executed.

..//steve

Jaakko Sundquist wrote:

> Hi again Steve,
>
> Thanks for the clarification. Actually I guessed that you intended to mean
> BEs instead of BGs, but I just wanted to make sure.
> As for the service paradigm, I guess the main thing is whether the
> gatekeeper to which a terminal/user is registered is located in the Home
> Administrative Domain or in the Visited Administrative Domain. I.e. is an
> incoming call always routed to a gatekeeper in the user's Home
> Administrative Domain so that the call processing logic can be executed
> always in the user's home environment?
> I seem to remember that Ericsson were quite keen to include this paradigm in
> the Annex H (that is what Chapter 7 of the draft annex should explain ->
> contributions are welcome ;-).
>
> -Jaakko
>
> > -----Original Message-----
> > From: EXT Stephen Terrill [mailto:stephen.terrill at ericsson.com]
> > Sent: 13. April 2000 16:38
> > To: ITU-SG16 at mailbag.cps.intel.com
> > Subject: Re: [H.323 Mobility:] questions on MTD-016
> >
> >
> > Hi Jaakko,
> >
> > Perhaps it should have been a BE instead of a BG, sorry for
> > the confusion.  I understood from the previous work, not all
> > of which I have had the priveledge to be a part of, the
> > communication could be directly between the two networks, or
> > via the BEs.
> >
> > Regarding the service execution paridigm what "services" are
> > you considering?
> >
> > Regards,
> >
> > ..//steve
> >
> > Jaakko Sundquist wrote:
> >
> > > Hi Stephen,
> > >
> > > I have a couple more questions.
> > >
> > > First, what exactly is the BG in your contribution? I know
> > that there is
> > > such an element in GPRS and it is used in cases, when the
> > visited PLMN
> > > always routes the packets of the visiting user to the
> > user's home PLMN. I
> > > assume that this BG is supposed to serve a similar purpose,
> > am I right?
> > >
> > > Second, based on the above mentioned purpose of the BGs and
> > to the fact that
> > > in your contribution you state that the HLF selects a
> > gatekeeper in the home
> > > network of the user to which the terminal/user will be
> > registered, I assume
> > > that this model that you are proposing is only applicable
> > for the "Virtual
> > > Home Environment" model (i.e. service execution in the home
> > network). Am I
> > > right in this assumption, and if not, could you explain how
> > this model could
> > > be used in the "Service Execution in the Visited Network" model?
> > >
> > > Furthermore, I would not use the terms home/visited
> > network, because there
> > > are evidently differing views on what a network means. I
> > suggest that we use
> > > the already defined terms Home/Visited Administrative
> > Domain instead for the
> > > meaning of home/visited network that I think you're thinking of.
> > >
> > > -Jaakko
> > >
> > > > -----Original Message-----
> > > > From: EXT Stephen Terrill [mailto:stephen.terrill at ERICSSON.COM]
> > > > Sent: 13. April 2000 14:42
> > > > To: ITU-SG16 at mailbag.cps.intel.com
> > > > Subject: Re: [H.323 Mobility:] questions on MTD-016
> > > >
> > > >
> > > > Hi,
> > > >
> > > > I shall try to answer some of these questions below.
> > > >
> > > > Regards,
> > > >
> > > > ..//steve
> > > >
> > > >
> > > >
> > > > "Kumar, Vineet" wrote:
> > > >
> > > > > Stephen,
> > > > >
> > > > > I have a couple of questions on your contribution MTD-016.
> > > > These are:
> > > > >
> > > > > 1. H.323 already has mechanisms for discovering the
> > > > gatekeeper. Are you suggesting in your contribution that the
> > > > terminal should discover the VLF instead of the visiting
> > > > gatekeeper ? Or, are you assuming that the VLF is integrated
> > > > in the visiting gatekeeper ?
> > > >
> > > > This can be discussed - I was of the opionion that we should
> > > > discover the VLF and send the registration to the home
> > > > environment after that.  However, we haven´t agreed on the
> > > > role of the VLF, and visited gatekeeper, home gatekeerp and
> > > > HLF - when we come to agree on what these are, my
> > proposal may change.
> > > >
> > > > >
> > > > >
> > > > > 2. In H.323, authentication of the terminal and the
> > > > gatekeeper is done at the time of discovery. In fact, in
> > > > H.323 all messages between the terminal and the gatekeeper
> > > > can be authenticated and the message integrity preserved. In
> > > > your contribution, authentication is done at the time of
> > > > registration. Why is this preferable to what is already in H.323 ?
> > > >
> > > > I would be interested to understand which gatekeeper you were
> > > > considering should do the authentication.  I would assume
> > > > that the real authentication would have to be done at home -
> > > > as such it would be necessary to find the visited network
> > > > services, and then register/authenticate at home.
> > > >
> > > > >
> > > > >
> > > > > 3. What is the reason for the information flow from the HLF
> > > > to the home gatekeeper, and from the home gatekeeperr to the
> > > > HLF ? I don't think we can assume that there is only one home
> > > > gatekeeper that the terminal may be using. In fact, the home
> > > > gatekeeper may not have any information about the user.
> > > >
> > > > I certainly don´t assume that there is only one home
> > > > gatekeeper.  I assume that there will be a number of home
> > > > gatekeepers, but perhaps only one (or few) HLFs.  In this
> > > > case, we need an function to select the gatekeeper that the
> > > > user is going to camp on - and this may depend on load,
> > > > subscriber profile, policy - or a lot of things.
> > > >
> > > > >
> > > > >
> > > > > Regards,
> > > > > vineet
> > > >
> >



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