QoS-Aware Routing Schemes Based on Hierarchical Load-Balancing for Integrated Services Packet Networks

This paper presents a load balancing method to improve network utilization when static routing algorithms are employed. Static routing algorithms can generally be reduced to a path assignment problem with the aim of minimizing a cost function: i.e., maximizing network revenues. Unfortunately the problem, when multiple constraints such as different QoS traffic classes are present, is computationally intractable. Load balancing methods are heuristics that allow the identification of local minima of the cost function that hopefully are close to the real optimum. The load balancing method we propose is based only on static information about the average traffic load of each traffic relation: a piece of information which can easily be attained in telecommunication networks. The path-selection strategy is defined in terms of Set Theory and its performance is evaluated via simulation by comparison against standard Minimum-Hop path selections. Simulation results show that low priority traffic benefits significantly from the more balanced load obtained with our solution.