Traffic engineering for inter-domain optical networks

Abstract

Because of increasing demands for network bandwidth and the advances in WDM technologies, it is expected that IP (Internet Protocol) over Wave Division Multiplexing (WDM) will be the infrastructure for the next generation Internet by carrying IP packets over WDM. As this infrastructure matures, a number of important control issues are surfacing. One of them is traffic engineering, which concerns network performance optimization. This thesis presents a new approach to the congestion avoidance problem for wavelength-routed inter-domain networking under dynamic traffic demands where IP traffic is directly routed over WDM. The main idea is to adapt the underlying optical connectivity by measuring the actual traffic load over the existing lightpaths continuously and reacting to the load changes by adding or tearing down lightpaths. We avoid load instability directly by setting up a lightpath when congestion occurs or by tearing down a lightpath when the congestion is relieved. For the decision of setting up or tearing down lightpath, we propose a traffic engineering algorithm. The algorithm is characterized by two system parameters, high threshold (H) and low threshold (L). A simulation is conducted with different network topologies. The simulation results show the improvement we achieved in term of packets loss, resource utilization, blocking probability and delay.