Subject: [IPTEL] Requirement relating to multicast

From: "Cullen Jennings" <[email-masked]>
Date: Fri, 19 Oct 2001 11:39:03 -0700

I think it should be a requirement of the GW to LS protocol that it does not
require multicast. I can imagine scenarios where the size of the ITAD on the
network was larger than the space on the network where multicast would
route.

Cullen

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From: "Roy, Radhika R, ALCTA" <[email-masked]>
Date: Fri, 19 Oct 2001 21:55:22 -0400

Cullen:

Please see my comments below [RRR].

Radhika

From: Cullen Jennings [mailto:[email-masked]]
Sent: Friday, October 19, 2001 2:39 PM

require multicast. 

[RRR] How does one to make discovery? Are you suggesting pre-provisioning?
Or, do you like to use DNS stuff-like things where the list of LSs or GWs to
be provided?

I can imagine scenarios where the size of the ITAD on the
network was larger than the space on the network where multicast would
route.

[RRR] Yes, you are right especially in the case of intra-ITAD. That is why,
in the draft (draft-roy-sipproxy-ls-gw-discovery-00.txt), alternative
schemes to multicasting for discovery have been proposed. We do not need
either a heavy-weight discovery mechanism or a very elaborate scheme for
multicasting for the intra-ITAD.

[RRR] More discussion along this will be posted soon.

Cullen

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From: "Roy, Radhika R, ALCTA" <[email-masked]>
Date: Sun, 21 Oct 2001 21:30:43 -0400

Cullen:

Radhika

-----Original Message-----
From: Cullen Jennings [mailto:[email-masked]]
Sent: Friday, October 19, 2001 11:29 PM
To: Roy, Radhika R, ALCTA; [email-masked]
Subject: RE: [IPTEL] Requirement relating to multicast

I think we could definitely use some more discussions about provisioning of
VoIP components. The discovery of PS, GW, LS and so on seems closely related
to provisioning issues.

I don't really see any reason that a GW discovering a proxy it connects too
has much to do with TRIP. (And I do see the irony of this statement along
with my other email thread on how many protocols do I need to implement :-)

[RRR] Without discovery, a LS will not know about GWs if they are not
pre-provisioned. In TRIP, it has been assumed that LSs among the different
domains are pre-provisioned as it is done in the case of BGP. In
inter-domain, it may make sense because of inter-carrier cases. In TRIP,
there is nothing mentioned how a LS receives the information of the GWs. 

[RRR] The relationship between the GWs and LSs is the one that belongs to
the intra-ITAD (or intra-domain). Now you are making the assumption that
this is also can be pre-provisioned. This is your idea and if you want to do
this, no one forcing you to do otherwise. It is your "own" implementation
decision. But people want to see that there should be a standardize
mechanism for communications for the intra-ITAD: GWs <-> LSs and LSs <->
LSs. TRIP does not specify how these communications take place in intra-ITAD
situations. Unless LSs get the required information (e.g., E.164 addresses),
it will NOT be able work. TRIP does not need Email ids, URL Ids, etc.

[RRR] Let us not down play the communications scenarios for the intra-ITAD
just by saying that pre-provision mechanisms are good enough. For
intra-ITAD, there are different types of GWs: 1. Telephony GWs (e.g., E.164)
and 2. SIP-H.323 GWs. The addresses that we need deal with can be E.164,
email IDs, URL IDs, etc. (TRIP addresses only E.164). Unlike TRIP, we need
address resolution only, not route propagation.

[RRR] For GWs <-> LSs and LSs <-> LSs communications, we need: 1. Discovery
and 2. Information/Data transfer between GWs <-> LSs and LSs <-> LSs. For
discovery, there can be a. multicasting, b. pre-provisioned, c. DNS-like
scheme, and d. others. For information/data transfer, we may use the same
message sets what has been used in TRIP with modifications, but it needs to
meet intra-ITAD requirements. You seem to be pre-occupied with multicasting
only without seeing the complete picture.

I don't know, am I missing the boat on this one. I guess it comes back to
what are the requirements of TRIP.

[RRR] I guess that you are missing some points as explained above.