Subject: Re: GLP, number portability and wireless subscribers

From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 09 Mar 1999 16:06:46 -0500

Greg Zhang wrote:
> 
> One approach is to introduce hierarchy among the GLP speaking Internet
> telephony gateways. Instead of having a flat network of gateways, a
> hierarchy is built among the gateways. In a way that is similar to PNNI,
> the gateways becomes members of a peer group (PG). A peer group
> leader (PGL) is elected in a group. PGLs in one level becomes peers
> on the next level. And the process of PGL election process repeats
> on the new level. The hierarchy building is finished when all gateways
> are tied into one peer group at the highest global level.

The use of a hierarchical arrangement of LS's seems orthogonal to the
scope issue. We would still need to specify the encoding of scopes,
interpretation of scopes, and be able to configure LS's about whether to
propagate routes with particular scopes or not. We'll need to do this
with the current intra-domain and inter-domain model also. In a sense,
the current model contains a two-level hierachy. How does expanding this
hierarchy make the problem easier? It seems to complicate the protocol,
if anything. 

-Jonathan R.

-- 
Jonathan D. Rosenberg                       Lucent Technologies
Member of Technical Staff                   101 Crawfords Corner Rd.
High Speed Networks Research                Holmdel, NJ 07733
FAX:   (732) 834-5379                       Rm. 4C-526
EMAIL: [email-masked]
URL: http://www.cs.columbia.edu/~jdrosen

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From: "Greg Zhang" <[email-masked]>
Date: Tue, 9 Mar 1999 12:12:37 -0800

>> I think to handle this type of cases correctly, we need to introduce a
>> concept of scope for the advertisement. Gateways in CA will advertise
>> the 800 number for company X in CA while gateways in NY will
>> advertise the same 800 for company Y in NY. The advertisement from
>> the CA domain does not get propagated to the NY domain and vice
>> versa. This way the numbers that are locally significant and are being
>> administrated locally stays local. This however does not prevent the
>> same 800 number being used by upper level for a third customer.
>
>A sensible idea, but seems hard to do. How does one represent scope? How
>does one encode the notion that "this number is valid within the greater
>new york metropolitan area", or "northern california" into a protocol?

Within a peer group, the relationships are peer to peer. The distributed
database is synchronized among all members in the peer group. At
the peer group leader, policies are installed to control the aggregation
and propagation of content of the database to the upper level. This way
a peer group becomes a natural scope. For numbers that are only
locally meaningful, they are not propagated by the peer group leader
to the next level.

With the establishment of peer groups and the hierarchy, updates are
limited to a peer group. They can be aggregated at peer group leader.
Updates and synchronization of a database are no longer global.
This will give the protocol a higher degree of scalability. The forming
of the peer groups and the hierarchy is dynamic. It allows the protocol
to react to the changes in topology or connectivity in the network.

- Greg

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