Utilization of alternate communication paths is a common technique to provide protection of transmission against failures of network nodes/links. However, a noticeable delay is encountered when calculating the relevant sets of disjoint paths using the available algorithms (e.g., using Bhandari's approach). This, in turn, may have a serious impact on the ability of a network to serve dynamic demands (i.e., characterized by a relatively short duration time). To provide a solution to this problem, in this article we introduce an approach to pre‐compute the sets of disjoint paths in advance to be able to start serving the demands shortly after their arrival. Our approach is based on the observation that 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 end nodes of a demand. In particular, 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. A new method to calculate the cheapest end‐to‐end cycles based on the so called basic cycles is introduced, which, as verified for real network topologies, reduces up to 70% the time needed to establish node‐disjoint paths (compared with the results obtained for the reference Bhandari's scheme). © 2017 Wiley Periodicals, Inc. NETWORKS, Vol. 70(4), 308–326 2017

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The concept of alternate paths has been shown in the literature to provide fast response of a network to failures of its elements (nodes/links) affecting flows along the primary communication paths. Various approaches have been proposed to reduce the time necessary to redirect the respective flows onto the alternate paths.In this paper, we focus on another important objective, that so far has not received much attention, i.e., reduction of the overall time needed to calculate the set of working and alternate paths. The issue is important e.g., in the case of reactive approaches to survivable routing (if a failure of a network element leads to multiple attempts to determine the respective alternate paths), or when performing the periodic updates of the resilient routing scheme in the global scale.The aim of this paper is to present the analysis of time efficiency of our approach to provide the global set of end-to-end disjoint paths in comparison to the reference Bhandari's scheme. In particular, after describing the respective examples of our algorithm execution, we show (based on simulations) that it is possible to establish the sets of primary and alternate paths up to 70 times faster, compared to the common existing reference schemes.