Terminal-pair reliability in ATM virtual path networks

Abstract

Terminal-pair reliability (TR) in an asynchronous transfer mode (ATM) virtual path (VP) network corresponds to probabilistic quantization of robustness between two VP terminators, given a VP layout and failure probabilities of physical links. Existing TR algorithms are not viable for ATM VP networks owing to either high complexity or failure dependency among the VPs. The paper proposes two efficient algorithms for TR computation between two VP terminators by means of variants of path-based and cut-based partition methods which have been effectively used for TR computation in traditional networks. The first variant, called the path-based virtual path reliability (PVPR) algorithm, partitions the search space based on a physical path embedding the shortest route of VPs from the source to the destination terminator. The second variant, called the cut-based virtual path reliability (CVPR) algorithm, in lieu, performs the partition on the basis of a physical cutset separating the source from the remaining terminators. In both algorithms, each subproblem is recursively processed by means of partition until the source and destination terminators are contracted or disconnected. Experimental results reveal that, CVPR outperforms PVPR with respect to computation time. Moreover, compared to one of the most promising TR algorithms, both CVPR and PVPR exhibit superior performance. The two algorithms and their promising results consequently facilitate the real-time computation of the reliability or robustness of ATM VP networks.