Abstract: The present invention relates generally to restoration of services in a network. More particularly, the invention encompasses a scheme for randomized selection of equal cost links during restoration in a communication network. The invention further includes multiple schemes for restoring services. The network could consist of optical, ATM, FR, or IP/MPLS switches and cross-connects.

Abstract: A method and system provide capacity-efficient restoration within an optical fiber communication system. The system includes a plurality of nodes each interconnected by optical fibers. Each optical fiber connection between nodes includes at least three channel groups with different priority levels for restoration switching in response to a connection failure. The system maintains and restores full-capacity communication services by switching at least a portion of the channel groups from a first optical fiber connection to a second optical fiber connection system based on the priority levels assigned to the channel groups. Service reliability is effectively maintained without incurring additional costs for dedicated spare optical fiber equipment by improving idle capacity utilization.

Abstract: The present invention relates generally to restoration of low priority services in a network. More particularly, the invention encompasses a method and an apparatus for delaying the start of the restoration of low priority services in a communication network. The invention further includes multiple schemes for restoring low priority services. The network could consist of optical, ATM, FR, or IP/MPLS switches and cross-connects.

Abstract: Data are rerouted over a network having a uniform-capacity Tandem Connection by detecting a failure in a link in a path, maintaining the path through a Tandem Connection that does not include the failed link, and rerouting the data through the Tandem Connection based on information embedded in a tandem layer in the data, and independent of the constituent payload capacities within the tandem connection.

Abstract: Data are rerouted over a network having a uniform-capacity Tandem Connection by detecting a failure in a link in a path, maintaining the path through a Tandem Connection that does not include the failed link, and rerouting the data through the Tandem Connection based on information embedded in a tandem layer, and independent of the constituent payload capacities within the tandem connection.

Abstract: A method and system provide capacity-efficient restoration within an optical fiber communication system. The system includes a plurality of nodes each interconnected by optical fibers. Each optical fiber connection between nodes includes at least three channel groups with different priority levels for restoration switching in response to a connection failure. The system maintains and restores full-capacity communication services by switching at least a portion of the channel groups from a first optical fiber connection to a second optical fiber connection system based on the priority levels assigned to the channel groups. Service reliability is effectively maintained without incurring additional costs for dedicated spare optical fiber equipment by improving idle capacity utilization.

Abstract: A method and system provide capacity-efficient restoration within an optical fiber communication system. The system includes a plurality of nodes each interconnected by optical fibers. Each optical fiber connection between nodes includes at least three channel groups with different priority levels for restoration switching in response to a connection failure. The system maintains and restores full-capacity communication services by switching at least a portion of the channel groups from a first optical fiber connection to a second optical fiber connection system based on the priority levels assigned to the channel groups. Service reliability is effectively maintained without incurring additional costs for dedicated spare optical fiber equipment by improving idle capacity utilization.

Abstract: 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.