Patent ID: 6452906
Filing Date: 2002-09-17
Classification: H04J,H04Q

Abstract:
A method for detecting a fault in a Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) network, the method comprising the steps of:receiving in a first network element a fault indication in the form of at least one of a failed signal, a degraded signal, and an alarm indication signal in the path (AIS-P) associated with the fault; generating in the first network element a fault isolation signal in the path (FIS-P) in response to receiving the fault indication, the FIS-P comprising a synchronous payload envelope (SPE) having a plurality of bytes including a plurality of path overhead (POH) bytes, each byte comprising a plurality of bits, wherein all of the bits in the bytes of the SPE, except for at least one of the plurality of POH bytes, are set to all ones; and generating an AIS-P by the first network element after a predetermined period of time after beginning the step of generating the FIS-P.