Failure definition w.r.t. SONET/SDH and Protection/Restoration

["Diego Caviglia" <Diego.Caviglia@marconi.com>]

Hi all,
              is it defined somewhere, with respect to SDH/SONET, which
defect has to be consider as a failure?

It seems to me that for interoperability could be useful to have a list of
defect that must be considered as failure, the same applies for defect that
optionally can be considered as defect.

May be also a communication between restoration TNEs in order to agree on
the list could be useful.

Does anyone agree on that?

Regards

Diego

PS I apologise if the list is defined somewhere but I wasn't able to find
it.