New QOS Routing Algorithm for MPLS Networks Using Delay and Bandwidth Constraints

Abstract

Multi- Protocol Label Switching (MPLS) has been proposed as a new approach which combines the benefits of interworking and routing in layer 3 and layer 2 i.e Network layer and Data Link Layer. But its major technological significance lies in implementing Traffic Engineering. The most important requirement of TE is that the characteristics, as well as resource availability, on links on the network (in addition to bandwidth that would be used for cost computations) be propagated across the network to allow efficient choice of possible TE LSP paths. In this paper we propose a new constraint based routing algorithm for MPLS networks. The proposed algorithm uses both bandwidth and delay constraints. It means that the delay of the path which is computed by the algorithm is less than or equal to the delay constraint value and the residual bandwidth of all the links along the computed path must be equal to or greater than the bandwidth constraint value. In the proposed algorithm best path is computed based on avoiding critical links to reduce call blocking rate, deleting the paths which are not satisfying the bandwidth and delay constraints to reduce complexity of the algorithm and using shortest path algorithm to reduce path length. The proposed algorithm also compares two different topologies to study the performance of our proposed algorithm.