Abstract
Multi-Protocol Label Switching (MPLS) has been considered to be a promising solution to achieve end-to-end QoS guarantees in Differentiated Services (DiffServ) domains [1].Based on the Service Level Specification (SLS) between customers and the ISP, traffic forecast mechanism is able to predict traffic demands between ingress-egress routers, and hence bandwidth guaranteed LSPs can be set up accordingly through the DiffServ domain. In this paper, we address the problem of computing multiple LSPs with heterogeneous bandwidth requirements, while the overall network link cost is optimized. We first prove that finding a set of feasible LSPs with bandwidth constrained is NP-complete, and then propose an efficient heuristic with global network resource coordination over individual traffic aggregates. By simulation we show that the proposed coordinated path section (CPS) scheme obtains better overall LSP cost and lower bandwidth consumption compared with existing bandwidth constrained routing algorithms.