Network Graph Transformation Providing Fast Calculation Of Paths For Resilient Routing

Protection of transmission against failures can be appropriately dealt with by alternative paths. However, common schemes (e.g., Bhandari's scheme) are characterized by a remarkable delay while determining the transmission paths. This in turn may have a serious impact on serving dynamic demands (characterized by relatively short duration time).As a remedy to this problem, we introduce an approach to pre-compute the sets of disjoint paths in advance to be able to start serving the demands once they have arrived. In particular, since the issue of establishing a set of node-disjoint paths is equivalent to the problem of determining the cheapest cycle in the network topology traversing the demand end nodes, we propose a generalization of this scheme assuming that any pair of node-disjoint paths can be obtained by means of merging a number of basic cycles defined for a network topology. The main contribution of this paper is the BCMP method of cheapest end-to-end cycles formation based on basic cycles, which, as verified for real network topologies, reduces up to 70% the time needed to establish node-disjoint paths in comparison with results obtained for the reference Bhandari's scheme.