Study on integrated routing in IP-over-WDM networks

The problem of integrated routing in multifiber IP over WDM networks is studied in this paper. To solve this problem, a layered-graph is constructed and an algorithm, called integrated cost-based shortest path (ICSP) algorithm, is then proposed. ICSP can not only balance the traffic uniformly but also make a dynamic tradeoff between all the links in the layered-graph. A parameter rl is introduced to characterize the resource richness of an IP over WDM Network. Simulation results show that ICSP outperforms other algorithms significantly in terms of blocking probability in all the cases we studied, and the performances of other algorithms are affected by rl greatly. Because a multifiber network can be functionally equivalent to a single fiber network with limited wavelength conversion (WC), we make the first known attempt to investigate the impact of WC on dynamic integrated routing by studying the multifiber networks. Results show that the effect of WC depends on the granularities of label switched path (LSP) requests. If the granularity of each request is large, WC will improve the network performance; if the granularity of each request is small, WC will worsen the performance.