This document introduces alternate ways to perform certain operations
defined in RFC6378, "MPLS Transport Profile (MPLS-TP) Linear
Protection", and also defines additional behaviors. This set of
modified and additional behaviors together with the protocol defined
in RFC6378 meets the ITU-T's protection switching requirements.
This document introduces capabilities and modes. A capability is an
individual behavior. The capabilities of a node are advertised using
the method given in this document. A mode is a particular
combination of capabilities. Two modes are defined in this document:
Protection State Coordination (PSC) mode and Automatic Protection
Switching (APS) mode.
This document describes the behavior of the PSC protocol including
priority logic and state machine when all the capabilities associated
with the APS mode are enabled.
This document updates RFC6378 in that the capability advertisement
method defined here is an addition to that document.