Constraint-based path selection for new SLA acceptance

We need very effective traffic engineering tools to obtain quantitative end-to-end QoS guarantees in the DiffServ/MPLS network architecture, especially for dynamic service invocation. Through a negotiation process, the network operator (ISP) has to check if the new SLA can be accepted because of limited capacity resources on the path and existing traffic demands. For end-to-end congestion control with N quality of service levels (classes), an efficient heuristic algorithm is developed. For constraint-based path selection, an effective algorithm of the BFH type is used. The heuristic algorithm is compared with an algorithm based on an exact approach. In all numerical test-examples, the best possible result is achieved, but with significant computation savings.