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