Annex G and Roaming?
Edgar Martinez 
martinze at CIG.MOT.COM
Fri Apr 23 09:41:36 EDT 1999
I fully support the interworking between the
legacy mobile network VLR/HLR applications and
H.323 GK access via the SG to provide seamless
roaming between PLMN and IP networks. This
work will need to be addressed in Tiphon's WG7.
"Roy, Radhika R, ALCOO" wrote:
> Hi Everyone:
> Yes, I guess that the roaming has not been addressed in the present H.225.0
> AnnexG. To address roaming in a standard way, it will require to change the
> scope of Annex G.
> Annex G addresses the inter-domain communications.
> We have not yet standardized the basic roaming schemes even for the simple
> intra-domain communications.
> Last year, we discussed this problem, and some suggestions were made to
> solve this using the home and visiting GK. The discussion did not go too far
> to create a standard.
> It is an important topic, and let us create a standard in H.323 to support
> Let us understand that, in H.323, we are talking in the application layer,
> and not the networking layer. That is, roaming schemes have to be supported
> in the H.323 application layer that can take advantage of the mobility
> solutions provided in the network layer (e.g., mobile IP).
> Radhika R. Roy
> > -----Original Message-----
> > From: Espen Skjæran [SMTP:Espen.Skjaeran at ERICSSON.COM]
> > Sent: Friday, April 23, 1999 8:55 AM
> > To: ITU-SG16 at MAILBAG.INTEL.COM
> > Subject: Annex G and Roaming?
> > Hi all,
> > I've recently heard (unofficially) that some claim Annex G
> > (APC-1546/TD-20 in Monterey)
> > also to support roaming of users between different domains.
> > If this is true, I wonder how.
> > I can see how the AccessRequest/ValidationRequest might be sent from a
> > visiting domain to the home domain for per-call authorization. While
> > this might work in simple cases, it will hinder the use of services
> > while roaming.
> > I can not either see any mechanism to authorize the roaming
> > registration.
> > I am sorry to post based on "rumors", but this may change the scope of
> > Annex G significally, and I worry if this might affect future work on
> > roaming. As Tiphon has just started their work on roaming by analysing
> > existing roaming techniques in telco and datacom/IETF work,and not yet
> > reached any conclusion, it seems premature to use annex G
> > in its current state for roaming.
> > Espen
Edgar Martinez - Principal Staff Engineer
Email mailto:martinze at cig.mot.com
FAX 1-847-632-3145 - - Voice 1-847-632-5278
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