Re: Doubt in applying the transforms in SONET/SDH traffic parameters.

[Dimitri.Papadimitriou@alcatel.be]

Hi,

Read this sentence as "Each transform application is optional 
and must be ignored if zero, except MT that cannot be zero and 
is ignored if equal to one" during the traffic parameter 
processing at each hop. 

This means 1) when zero ignore the transform application 2) 
when non zero optional transform application except for the
MT field (at least equal to one) 1) when one ignore the 
transform application 2) when > 1 optional transform appli-
cation. In a sense 0 or 1 (for the MT) doesn't change the
number of Signal Type field occurrence.

In the example you gave here below, if such hypothetical
behavior occurs it is up to the upstream node policy to
decide whether or not the label (and thus the corresponding
bandwidth) allocation is acceptable for this ongoing request.

Hope this somehow clarifies,

Best regards,
- dimitri.

> Vinay Vernekar wrote:
> 
> Hi,
> The draft "draft-ietf-ccamp-gmpls-sonet-sdh-04.txt" specifies as
> follows for the traffic parameters -
> 
>   "Each transform is optional and must be ignored if zero, except MT
> that cannot be zero and is ignored if equal to one"
> 
> Is'nt it that the transform should be "mandatory" applied and not
> optionally as mentioned above. Consider for example, a request is
> received from an upstream peer with Signal Type as 6 indicating STS-3c
> SPE and NVC as 4 indicating a final signal which comprises of 4
> virtually concatenated STS-3c SPEs. This would mean a bandwidth of
> (155.5*4)Mbps requested by the upstream. Now if the LSR decides not to
> apply virtual concatenation, as inferred from the draft and gives back
> a mapping corresponding to STS-3c SPE, it would result in net
> bandwidth allocation of 155.5 Mbps only. Instead the LSR should reject
> the LSP request.
> The same argument holds good for other traffic parameters also.
> Kindly reqly back if I am missing something....
> Thanks in advance.
> 
> Regards
> Vinay
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