Hi Radhika et al,
I'm quite well aware that H.323 (as any communication protocol) is described
in the context of a network. In the case of H.323 all communications take
place on a packet based network.
>From H.323 Chapter 3: "3.34 packet based network (also network): Any
shared, switched, or point-to-point medium which provides peer-to-peer
communications between two or more endpoints using a packet based transport
protocol."
In other words H.323 defines "network" as the underlying means for
transporting H.323 protocols. I have nothing against that definition, but
inherent in this definition is the notion that this network does not have
any clear boundaries. I.e. all H.323 zones and domains that can communicate
with each other belong to the SAME network based on this definition.
Now, if we want to use the terms home/visited network, the question is:
What is the home network of a user? In other words what are the boundaries
in terms of network addresses, etc. of the part of the underlying network
(e.g. the Internet) that is defined as being the home network of the user.
Once we have defined the home network, we can, of course, easily define all
the other parts of the underlying network as visited network(s).
I have understood that most of the ad hoc group members have used the term
home network as a synonym for Home Administrative Domain (similarly for the
visited network/Domain). However, I understand that at least you, Radhika,
have a quite different view on this. My understanding is that according to
you there could be several "networks" even inside a zone, with perhaps one
of them being a user's home network (and the others visited networks for the
user). These two views are in contradiction to each other and that is why I
did not want to use these terms at least before they are clerly defined.
I'll also remind you that in the definitions of Annex H, the terms
Home/Visited/Serving Administrative Domain are already defined and thus no
ambiguity should arise when using them.
I hope this clarifies my worries.
-Jaakko
> -----Original Message-----
> From: EXT Roy, Radhika R, ALARC [mailto:rrroy@att.com]
> Sent: 13. April 2000 16:06
> To: Jaakko Sundquist; ITU-SG16(a)mailbag.cps.intel.com
> Subject: RE: [H.323 Mobility:] questions on MTD-016
>
>
> Hi, Jaakko:
>
> I am just pointing out to your one of your comments only: "..what a
> "network" means..."
>
> The term "NETWORK/NETWORK ADDRESS" is well defined in H.323.
>
> Please see Rec. H.323. The entire Rec. has been described in
> the context of
> the network. More specifically, Sections 3, 6.4, 7.1, 7.1.1, and many
> others. In this context, please also "Section 7.1.1 - Network
> Address ."
>
> In fact a network can be any packet network: IP, ATM, etc.
> More importantly,
> H.323 is for "Packet-Based Networks (PBN)."
>
> Are you questioning the fundamental basis of H.323?
>
> Let us NOT create a debate that does not exit.
>
> In the same token, there can be home network address, visited network
> address, target network address, etc.
>
> Hope this helps.
>
> Best regards,
> Radhika R. Roy
> AT&T
>
> > -----Original Message-----
> > From: Jaakko Sundquist [SMTP:jaakko.sundquist@nokia.com]
> > Sent: Thursday, April 13, 2000 8:20 AM
> > To: ITU-SG16(a)MAILBAG.INTEL.COM
> > Subject: Re: [H.323 Mobility:] questions on MTD-016
> >
> > 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@ERICSSON.COM]
> > > Sent: 13. April 2000 14:42
> > > To: ITU-SG16(a)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
> > >
>
