Subject: draft-shiomoto-ccamp-lsp-hierarchy-bis-00.txt

From: "Don Fedyk" <[email-masked]>
Date: Tue, 8 Nov 2005 10:06:05 -0500

Hi

Thanks for the presentation yesterday. A thought occurred to me about
the numbered versus unnumbered issue in your draft. (Note I will not
refer to the multiple instances of the control plane since as discussed
in the meeting I think this should be out of scope).   

What I like about the unnumbered identifiers are they are hierarchical
under the GMPLS node ID. I would suggest that even when an interface is
numbered it could have an unnumbered identifiers as well and the
numbered interface not be assumed to be advertised but assumed instead
to be an identifier. It is in my opinion a special case when the
numbered interface is out of the same address plan as the GMPLS control
plane.  Generally we should not assume this is true and separating the
local identifier context from the GMPLS control addressing has
advantages.  (already illustrated by your draft). 

If we treated all links this way they could have different identifiers
for the purpose of identification and signaling in the link identifier
space (e.g. IP, MAC, NSAP etc) and uniformly use unnumbered identifiers
for all routing and TE advertisement.  I realize this is not the way
that unnumbered links came about but this might be the more
"generalized" way to address this.

Did you consider this option?

Regards,
Don

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From: Kohei Shiomoto <[email-masked]>
Date: Wed, 09 Nov 2005 06:38:03 +0900

Hi Don

Thank you for your comments.

> in the meeting I think this should be out of scope).   

As I noted in the response to Dimitri comments, the target control plane
instance is useful when we have multiple layer network where there is a
client-server relationship between them.

> under the GMPLS node ID. I would suggest that even when an interface is

We might want to use unnumbered when we need to save the address space
as you said.

> to be an identifier. It is in my opinion a special case when the

I am not clear what makes us to assign both numbered and unnumbered
address on the same interface. Maybe I miss something.

> advantages.  (already illustrated by your draft). 

Yes. The local interface identifier should come from different address
space of the GMPLS control plane address.

> Did you consider this option?

You are saying that numbered interface is used for GMPLS and different
identifier is used for upper layer instance, aren't you (unnumbered
address is used in GMPLS domain)? It might be a option when we want to
advertise the TE-link in GMPLS control plane as well as in the upper
layer instance. Please correct me if I misunderstand your point.

Thanks,
Kohei