Differentiated multi-layer integrated routing in IP over WDM networks

Abstract

We investigate the problem of static and dynamic differentiated Multi-layer Integrated Routing (MLIR) for efficiently provisioning traffic connections of arbitrary bandwidth granularities in IP over WDM networks. The priority-based Integer Linear Programming formulations for static MLIR problem are firstly given. Then a new simplified weighted graph model for the integrated IP over WDM networks consisted of optical routers with multi-granularity optical-electrical hybrid switching capability is proposed. Based on the proposed graph model, we develop an dynamic MLIR scheme called differentiated weighted fair algorithm (DWFA) employing adaptive admission control (routing) strategies with the motivation of service/bandwidth differentiation, which can jointly solve three sub-problems of multi-layer routing by simply applying the shortest-path algorithm. The major objective of the DWFA is fourfold: (1) quality of service routing for various priorities traffic requests; (2) blocking fairness for various bandwidth granularities traffic requests; (3) adaptive routing according to the policy parameters from service provider; (4) lower computation complexity. Simulation results show that DWFA performs better than traditional overlay routing schemes such as optical-first-routing and electrical-first-routing, in terms of traffic blocking ratio, traffic blocking fairness, average traffic logical hop counts and global network resource utilization. Our developed scheme is proved to be a simple, comprehensive and practical framework of MLIR in IP over WDM networks for service providers.