Comparison of Multi-service Routing Strategies for IP Core Networks

Service differentiation in IP core networks may be supported by dedicated path selection rules. This paper investigates the degree of service distinction achievable when common routing strategies, like ECMP, SWP and WSP, are applied to two traffic classes separately and in different combinations. One traffic class requires low latencies, while the other is considered as best-effort traffic. A Maple program has been developed that evaluates network performance characteristics, like maximal link utilization, and per-class measures, like mean end-to-end delay and mean number of hops, when paths are computed on demand with traffic demands arriving in arbitrary order. Realistic network topologies may be imported from the publicly available tool BRITE, while link capacities and traffic patterns are chosen randomly (with realistic constraints) in Maple. Experiments show that a comparable service differentiation may already be achieved with less sophisticated strategy combinations, which apply ECMP to the delay-critical traffic class.