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Communication networks are subject to many challenges leading to single or multiple failures of its elements. Example failure scenarios include unintentional failures due to scheduled maintenance activities or massive failures caused by disaster-induced events. Therefore, it is crucial to enhance the networks with redundancy and resilience mechanisms able to maintain the availability of network services after a failure. As these problems are often inherently hard to solve to optimality, the role of time-efficient approximation schemes is essential. In this paper, we highlight the selected problems of communication networks resilience addressed in this issue of Networks. Locked until 27.03.2021 due to copyright restrictions. This is the peer reviewed version of an article, which has been published in final form at [DOI: 10.1002/net.21940 ]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

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, VolV 70(4), 308–326 2017