Patent ID: 7398018

Claim:
Optical transmission equipment comprising: a pair of a work interface unit and a protection interface unit each accommodating an optical transmission line; and an add drop multiplexing unit commonly provided for the pair of a work interface unit and a protection interface unit, for selecting between respective optical signals being output from said interface unit pair to output either selected optical signal, wherein each interface unit of said interface unit pair includes a switchover controller, and each of said interface unit pair is mutually connected via a communication path so as to share status information among said switchover controllers, on occurrence of a failure in said work interface unit of said interface unit pair, said switchover controller of the work interface unit reports the failure via said communication path to said switchover controller of the protection interface unit prepared as an object for switchover, and then, the switchover controller of the protection interface unit sends a switchover request to the add drop multiplexing unit, thereby selecting the signal output from the protection interface unit, and wherein the add drop multiplexing unit includes a priority circuit in which high priority is set for a switchover request from the work interface unit, so that an effective out put side is to be switched over from the protection interface unit to the work interface unit, irrespective of the switchover request issued from in the protection interface unit.