ON ROUTING IN ATM NETWORKS

Alternative routing of calls has long been regarded in the telephone industry as a means of increasing call throughput and robustness in the telephone network. Given the great gains in performance offered by dynamic nonhierarchical routing in telephone networks, it is natural to consider dynamic routing of Virtual Circuits (VCs) in Asynchronous Transfer Mode (ATM) networks. However, unlike telephone networks, VCs have heterogeneous bandwidth characteristics and Quality of Service (QOS) requirements which the routing algorithm must take into account in order to optimize performance. In this paper we attempt to classify ATM networks according to the network characteristics which have the greatest bearing on the performance of dynamic routing algorithms. We classify ATM networks according to the homogeneity of sources and the presence of statistical multiplexing. We then discuss appropriate routing algorithms for each class of ATM network and suggest methodologies for performance evaluation.