PNNI routing algorithms for multimedia ATM Internet

PNNI (Private Network-Node Interface) routing protocol is one of the most significant technologies for realizing a high-speed Internet backbone using ATM networks. This paper gives an overview of PNNI protocol, standardized ATM Forum. The authors also propose a new QOS (Quality-Of-Service) routing algorithm for PNNI protocol that can find a path guaranteeing several QOS parameters requested by users. It is known that a routing problem is NP-complete, if the number of additive QOS parameters, such as delay and cost, are more than or equal to two. Although a number of heuristic algorithms have been proposed recently to solve this problem, the appropriate choice of routing algorithms is still an open issue. In this paper, we propose a new heuristic routing algorithm, while being compliant with PNNI routing and signaling specification in the ATM Forum. The performance of algorithms is evaluated by simulation with a various network topologies and loading scenarios. These simulation results demonstrate that the proposed scheme improves the performance while reducing computational complexity. Furthermore, this paper gives an overview of a testbed system that has been developed for evaluation of actual PNNI routing and signaling protocol with the proposed QOS routing capability.