Research On Routing Algorithms In IP/MPLS Over WDM Network

The prevalence of IP service and the fast development achieved in high-speed router field, in particular the wide employment of WDM technology, have put forward the evolution of next-generation network architecture. Due to its excellent functions such as QoS and TE, as well as its characteristic of connection-oriented, MPLS technology is expected to be chosen as the adaptation layer in the integration of IP and WDM, which leading to the emergence of the two-layer network architecture consisting of IP/MPLS data network and the underlying WDM optical network, i.e., IP/MPLS over WDM network.Network control for IP/MPLS over WDM network can be classified as the overlay, augmented, and peer models. In the first two models, the IP/MPLS layer and the optical layer only have the resource information of their respective layers. In the peer model, all the resource information is known to both layers; hence, it can potentially achieve better resource utilization. Unfortunately, the peer model approach is generally not acceptable to the operators if the IP/MPLS layer and optical layer belong to two different administrations. In this paper, two simple and novel algorithms for routing labeled-switching path (LSP) requests based on the overlay model are proposed. One is called ILCC(IP/MPLS Layer Congestion Control Algorithm)which can alleviate the congestion in the IP/MPLS layer by limiting the length of feasible paths when setting up the LSPs, Another is CBSF(Consulted-Based Shortest Path Algorithm)which can utilize resources in both layers as in the peer model.Simulation results show that the proposed algorithms perform better than other routing algorithms for the overlay model.