Amendment 1 to Recommendation ITU-T G.8121/Y.1381 (2012) provides:

-          Updating the CW (Control Word) processes.

-          Updating some Insert/Extract processes and MIs for OAM such as AIS, LCK,and APS.

-          Add new OAM process for AIS/LCK reception and Lock Instruct process.

-          Add new process for Dataplane Loopback.

-          Update Trail Termination and Adaptation functions in align with the update each process.

-          Some editorial updates.