>> In transport networks we *never* have peer-2-peer OAM interworking. >> If it was required it would have explicitly been mentioned in >> the MPLS-TP requirements RFC. >Indeed, to have any peer to peer OAM simply removes the ability of the OAM to do its job. Neither of these statements is completely accurate. For example, the ITU produced Y.1712 that details the peer-peer interworking of ATM OAM per I.610 with the MPLS OAM described in Y.171. I think that the accurate statement is that OAM interworking is perhaps undesirable but trivial when the OAM semantics matches so that the interworking is syntactic translation, but very challenging (and perhaps sometimes impossible) when the semantics are different. (For "semantics to be different" it is enough for timer values to be different, let alone different fault states.) However, there are many cases where several OAM types co-exist in a single deployment. Perhaps the most relevant case is the widespread use of both EFM OAM (802.3 Section 57) with Y.1731 OAM. Y(J)S _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf