RE: Moving right along ...

[Yanhe Fan <yfan@axiowave.com>]

Hi, Zhi

>For the label value for SONET/SDH or the label description in the 
>generic draft, the label is defined as directly representing the 
>"timeslot". Now if I have a control plane controlled transport network 
>that goes through a ADM that is not control plane controlled, as:
>
>
>+--------+               +--------+               +--------+
>|        | ---1--------- |        | ----1-------- |        |
>|        | ---2--------- |        | ----2-------- |        |
>|  A     | ---3--------- |   B    | ----3-------- |   C    |
>|        | ---4--------- |        | ----4-------- |        |
>|        | ---5--------- |        | ----5-------- |        |
>+--------+               +--------+               +--------+
>
>Now imagine A and C is part of GMPLS, but B is just a legacy ADM. So at 
>A you have labels 1,2,3,4,5 (imagine these as in the SUKLM format) and C 
>has labels 1,2,3,4,5 incoming.
>
>Now imagine that at B, it actually has a fixed cross-connect that 
>connects A-1 (A's timeslot #1) to C-2 (C's incoming timeslot #2), A-2 to 
>C-3, A-3 to C-4, A-4 to C-5, A-5 to C-1.
>
>Now when A GMPLS sends a message to C, the label it uses is "1". 
>However, the connection/LSP associated with timeslot "1" is actually the 
>label of timeslot "2" at C. </z>

In this case, you're trying to use GMPLS to setup an LSP cross a node (B)
which can't understand GMPLS.

Now imagine A, B and C are all OXCs, can you setup an LSP A-B-C by using 
GMPLS if B can't understand GMPLS?

Now imagine A and B are LSRs, and B is a conventional router (can't
understand
MPLS), can you setup an LSP A-B-C?

Now imagine A, B and C are ATM switches, can you setup a svc if B can't
understand PNNI at all?

My point is that in order to make you case work, some additional work need
to
be done besie simply using GMPLS as singnaling protocol, becase some node on
the path is not GMPLS speakers. A and C needs the info of time slot aligment

between them. This can be done by some configurations, some link management 
protocls (LMP maybe) etc. As long as A and C have this piece of info,
eveything
works fine.

Yanhe