Patent ID: 7561795

Claim:
A method for protecting an optical telecommunication network against possible failures and signal degrades, the method comprising: connecting a plurality of nodes to a plurality of working resources; connecting the plurality of nodes to a plurality of protecting resources; operating protection switching between first working resources and first protection resources on a first protection layer using a first protection mechanism operating at the first protection layer; and operating protection switching between second working resources and second protection resources on a second protection layer using a second protection mechanism operating at the second protection layer, wherein if one of the plurality of nodes detects a failure that is correctable by said first protection mechanism, sending downstream to another one of the plurality of nodes an in-band Forward Protection Indication (FPI) signaling that disables the second protection mechanism with respect to the failure, wherein if one of the plurality of nodes detects a Bit Error Rate between a certain range, sending downstream to another one of the plurality of nodes an in-band Link Degradation Indication (LDI) signaling instructing the second protection mechanism to operate, wherein said first protection layer is a OTU-trail section layer and said second protection layer is a ODU path layer, wherein said first protection mechanism comprises any of an OTU trail protection mechanism and an ODU-SPRing span switch, and wherein said second protection mechanism comprises any of an ODU SNC switch and an ODU-SPRing ring switch.