System and method for achieving efficient coordination of protection switching

摘要

The delineation and quick invocation of protection switching is achieved by generating a protection indicator having an initial state at the point (e.g. in 115) that a transmission facility (e.g. 111) failure is detected and passing the indicator downstream. A switch that receives the indicator either increments or decrements the indicator in accordance with predetermined rules. However, a switch that receives the indicator when it reaches an active state immediately invokes protection switching if that switch is at the sink end (125,130,140) of an associated protection path. <IMAGE>