A virtual path routing algorithm for ATM networks based on the equivalent bandwidth concept

Abstract

The coexistence of a wide range of services with different quality of service (QoS) requirements in today's networks makes the efficient use of resources a major issue. It is desirable to improve network efficiency by adaptively assigning resources to services that have different bandwidth demands. Implementing Broadband Integrated Services Digital Networks (B-ISDN) therefore requires a network control scheme that can handle bursty traffic with unexpected fluctuations. The Asynchronous Transfer Mode (ATM) technology provides this flexibility by virtualizing network resources through the use of the virtual path (VP) concept. In this study, a method for designing a VP-based ATM network is proposed. The developed heuristic design algorithm applies VP routing and separation techniques to minimize the maximum link utilization under processing delay constraints. Each link is assigned a weight that reflects its current utilization. Using these weights, the VPs on highly utilized links are rerouted to less congested physical paths. The algorithm makes use of the equivalent bandwidth concept, which provides an efficient method to estimate capacity requirements of connection requests such that QoS requirements are met. The quality of the solutions achieved by the proposed method is compared to several competitors under varying network topologies and traffic conditions. The observations on the algorithm performance show that the developed method is able to facilitate an efficient use of network resources through the introduction of VPs.