Decentralized Robust Control for Dynamic Routing of Large Scale Networks

A variable structure decentralized controller for dynamic routing in multi-destination large-scale data communication networks is presented. A dynamic model, which can incorporate different processing delays at different nodes, is developed to describe the network dynamics. It is shown that the proposed controller guarantees stability and clears the queues of the system in the absence of external input flows. The controller also keeps the queue lengths bounded in the presence of external flow rates, which do not exceed a certain maximum flow rate (obtained by solving a LP optimization problem - there is no solution to the routing problem if these rates are exceeded). Furthermore, the controller is also robust with respect to variations in the processing delay constants. Some simulation results are presented to illustrate the controller's performance in a number of practical cases.