QoS routing algorithms for pre-computed paths

Abstract

Routing with multiple QoS constraints is known to be a NP-complete problem. In our previous work (QoSR/sub BF/ algorithm), we have shown that, for a number of specific QoS constraints, this problem can be solved in polynomial time, when a weighted fair queueing (WFQ) service discipline is employed. QoSR/sub BF/ is an on-demand algorithm. We propose a number of QoS routing algorithms for pre-computed paths, when all or some of the flow specification parameters and the amount of bandwidth that has to be reserved are not known a priori. We also show that the size of the routing table could be reduced, as paths satisfying some conditions could be neglected.