Abstract: A method and system for determining location and value of dispersion compensating modules (DCMs) in an optical network is provided. The method comprises evaluating possible DCM values and locations and successively adding selected combinations to the network until the dispersion limits of the network are met. This systematic method is applicable to a variety of network topologies. In one embodiment, the method for determining the location and value of the DCMs uses the amount of compensated effective dispersion over all lightpaths that pass through the DCM to select the combinations. In another embodiment, the method is repeated a number of times with different selections of DCM value and location combinations, and the method providing the least number of DCMs and the lowest DCM values is chosen.

Abstract: A method for selecting two maximally disjoint shortest paths between a source node and destination node in a network is provided. The method comprises determining a first explicit route between the source and destination nodes by using an original link cost for each link in the network, transforming the network by introducing conditional link costs, determining a second explicit route between the source and destination nodes in the transformed network taking into account the conditional link costs, and determining the two maximally disjoint shortest paths between the source and destination nodes by coalescing the first and second explicit routes. Beneficially, the step of introducing conditional link costs comprises adding additional parameters to links in the network and determining the conditional link costs depending on the position of each link relative to the first explicit route.

Abstract: A communication network is provided which includes a primary label switched path having a plurality of switching routers. The communication network includes a secondary label switched path which extends from a selected primary path switching router, bypasses a section of the primary path and rejoins the primary path at a position downstream of the selected switching router. The selected switching router is conditioned to re-route data intended for transmission on the primary path, onto the secondary communication path in response to a fault on the section of the primary path which is bypassed by the secondary path to restore data transmission.

Abstract: Methods, systems, computer readable media are provided which facilitate the selection of multiple paths through a network represented by a network topology which take into account shared risk which may exist between network resources. The method involves identifying a first path through the network topology from a source node to a destination node, the first path comprising a first sequence of network resources. For at least one shared risk group, a determination is made if any of the at least one shared risk group includes any of the first sequence of network resources, a shared risk group being a group of network resources within the network topology which have a shared risk. A topology transformation is performed of the network topology into a virtual topology which discourages the use of network resources in any shared risk group determined. A second path through the virtual topology is identified from the source node to the destination.