Fuzzy reasoning approach for QoS routing in B-ISDN

Efficient routing algorithms are required to guarantee the various quality of service (QoS) characteristics requested by the wide range of application s supported by Broadband Integrated Services Digital Networks(B-ISDN). Howe ver, it is known that various formulations of such a routing problem, with two or more additive or multiplicative QoS metrics in any possible combinat ion, is NP-complete. In this paper, we propose a heuristic approach based o n fuzzy logic. For each metric, a fuzzy membership function is defined to r eflect the QoS requirements from that metric. A fuzzy-inference rule base i s implemented to generate the fuzzy cost of each path based on the crisp va lues of the different metrics possibly used in the network links. The propo sed approach is tested with a wide variety of loads and the effect on diffe rent measures of performance is analyzed. Simulation results demonstrate th e capability of this approach to increase the throughput and utilization of the communication network, and provide a fair distribution of different co nnection requests.