06452906 is referenced by 16 patents.

An in-band fault detection and isolation system and method for networks such as Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) networks. Fault detection may be quickly and efficiently performed by a network without requiring modification to any add/drop multiplexers (ADMs) and/or without the involvement of an external network management system (NMS). To accomplish this without violating SONET/SDH standards, a new signal, called a fault isolation signal in the path (FIS-P), is proposed. The FIS-P may be used in lieu of an AIS-P to support special applications on certain digital cross connect (DCS)-to-DCS path segments. Moreover, the present invention may be implemented such that the behavior, of path terminating equipment (PTE) is unaffected.

Title
Fault detection and isolation in a synchronous optical network (SONET) and in a synchronous digital hierarchy (SDH) network
Application Number
9/137136
Publication Number
6452906 (B1)
Application Date
August 20, 1998
Publication Date
September 17, 2002
Inventor
Simon S Zelingher
Morganville
NJ, US
Peter M Dollard
Highlands
NJ, US
Sid Chaudhuri
East Brunswick
NJ, US
Thomas S Afferton
Bridgewater
NJ, US
Assignee
AT&T
NY, US
IPC
G01R 31/08
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