Abstract

Abstract — One of the key issues in providing end-to-end Quality of Service (QoS) guarantees in today’s networks is how to determine a feasible route that satisfies a set of constraints. In general, finding a path subject to multiple constraints is an NP-complete problem that cannot be exactly solved in polynomial time. Accordingly, several heuristics and approximation algorithms have been proposed for this problem. Many of these algorithms suffer from either excessive computational cost or low performance. In this paper, we propose a more efficient distributed algorithm namely Least-Cost Least-Delay (LCLD). The LCLD algorithm is a modified version of SF-DCLC algorithm. The proposed algorithm requires limited network state information at each node. The LCLD algorithm uses a weight function which is always able to find a least-cost least-delay path satisfying the delay bound, if such paths exist. The performance of proposed LCLD algorithm was evaluated using computer simulation. Simulation results show that LCLD outperforms several earlier algorithms in terms of overall network throughput, number of packet loss, number of received packets and end-to-end delay. The worst-case computational complexity of this algorithm, for a network graph with v nodes is equal with O(|v | 2). Index Terms — QOS routing, constraint based routing, LCLD algorithm, SF-DCLC algorithm I.

Citations