A randomized algorithm for finding a path subject to multiple QoS requirements

• Published in: Computer networks (Amsterdam, Netherlands : 1999) Vol. 36; no. 2; pp. 251 - 268
• Main Authors: Korkmaz, Turgay, Krunz, Marwan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2001; Elsevier Sequoia S.A
• Subjects: Algorithms; Multi-constrained path selection; Networks; QoS-based routing; Quality of service; Routing; Scalable routing; Selection; Studies; QoS-based routing; Scalable routing; Multi-constrained path selection
• ISSN: 1389-1286; 1872-7069
• DOI: 10.1016/S1389-1286(00)00209-7

An important aspect of quality-of-service (QoS) provisioning in integrated networks is the ability to find a feasible route that satisfies a set of end-to-end QoS requirements (or constraints) while efficiently using network resources. In general, finding a path subject to multiple additive constraints (e.g., delay, delay-jitter) is an NP-complete problem. We propose an efficient randomized heuristic algorithm to this problem. Although the algorithm is presented as a centralized one, the idea behind it can also be implemented in a distributed manner. Our algorithm initially computes the cost of the best path from each node to a given destination with respect to individual link weights and their linear combination. In this initialization step, Reverse–Dijkstra's algorithm is used K+1 times per path request, where K is the number of additive constraints. The algorithm then randomly traverses the graph, discovering nodes from which there is a good chance of reaching the final destination. This randomized search is a modification of the breadth-first search (BFS). Using extensive simulations, we show that the proposed algorithm provides better performance than existing algorithms under the same order of computational complexity.