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Re: MLN extensions question -- regions and/or layers?



Hi Martin, I thought that multi-layer would also be supported in addition to multi-region... Typically VCAT is used as part (but needs other adaptations such as GFP or POS) to get from a higher layer such as IP or Ethernet into the SDH server layer. It seems like we need a systematic way to describe multiple adaptations without having to describe all possible permutations. Hence I thought a list of supported adaptations whether between regions or layers would be more efficient. Also, for TDM hierarchies, I'd really want to know which ports have access to a finer granularity fabric and which don't. What would be wrong with having adaptations within a region? Its done all the time in the data plane.

Regards

Greg B.

Martin Vigoureux wrote:
Dear Greg,

both of your (a) and (b) examples correspond to operations
performed within a switching capability (i.e. TDM-SC)
while the sub-TLV here defined is designed and intended
to be used for cross-region operations, i.e. when passing
from a given switching capability to a different one.
"Adaptation" here describes a transition (from SCx to SCy with x!=y)
capability.

hope it clarifies.

best regards,

Greg Bernstein a écrit :
Hi all looking at the MRN extensions draft I've got two specific examples of "adaptation" I'd like to understand how to encode.
(a) SDH/SONET VCAT higher order (VC-3, VC-4) only supported
(b) SDH/SONET finer granularity switching capability. For example the ability to pull VT1.5, VT2 our of VC-3/VC-4 switch them and possibly pack them in.

Currently the draft has:

0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Switching Cap | Encoding | Switching Cap | Encoding | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ---snip--- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max LSP Bandwidth at priority 7 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Adaptation Capability-specific information | | (variable) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ In both the cases mentioned above the Switching Cap (1 and 2) would be the same TDM, similarly the encoding types in both (1 and 2) would be SDH.
So what would be in the Adaptation Capability specific info field?

Also, to get from SDH to Ethernet via VCAT and GFP (or whatever) would require multiple adaptations would those be represented in a single stack within the Adaptation Capability specific info field?

Regards

Greg B.

Adrian Farrel wrote:
Hi,

Now that the MLN requirements and protocol evaluation have completed last call with just a couple of comments, and now that we have more or less reached stability with our liaisons to the ITU-T on this subject, we need to look for a solutions I-D.

http://www.ietf.org/internet-drafts/draft-papadimitriou-ccamp-gmpls-mrn-extensions-04.txt has been running for some time and tracking both the requirements and the lacunae identified by the evaluation draft. It seems that this provides a good basis for the protocol work in CCAMP even if some elements might change.

Please express your support or otherwise for this I-D to become a WG draft.

Thanks,
Adrian







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Dr Greg Bernstein, Grotto Networking (510) 573-2237