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

[Igor Bryskin <i_bryskin@yahoo.com>]

Hi,

I completely agree with Greg. As far as adaptation capability is concerned there should be no difference between:
a) server and client layers belong to different regions;
b) server and client layer belong to the same region

Igor

Greg Bernstein <gregb@grotto-networking.com> wrote:
>  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
> >>>
> >>>
> >>>
> >>
> >
> >
>
> -- 
> ===================================================
> Dr Greg Bernstein, Grotto Networking (510) 573-2237

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