Traffic Engineering in Multi-Granularity, Heterogeneous, WDM Optical Mesh Networks Through Dynamic Traffic Grooming

In this paper, we investigate the problem of efficiently provisioning connections of different bandwidth granularities in a heterogeneous WDM mesh network through dynamic traffic-grooming schemes under traffic-engineering (TE) principles. Due to the huge amount of traffic a WDM backbone network can support and the large geographic area it can cover, constructing and upgrading such an optical WDM network can be costly. Hence, it is extremely important for network operators to apply traffic-engineering strategies to cost-effectively support different bandwidth-granularity services using only the appropriate amount of network resources. This requires an optical WDM network to have multi-granularity switching capability, and such a network tends to be a multi-vendor heterogeneous network. However, WDM network heterogeneity increases the difficulty and challenge of efficient traffic provisioning. In this paper, we present different TE issues which need to be carefully considered in such an optical WDM network and propose possible solutions and extensions for the Generalized Multi-Protocol Label Switching (GMPLS) optical network control plane. We extend an existing, generic, graph model to perform efficient traffic grooming and to achieve different TE objectives through simple shortest-path computation algorithms. We show that our approach is very practical and very suitable for traffic engineering in a heterogeneous, multi-granularity, optical WDM mesh network.