A multipath algorithm for premium traffic routing in Diffserv networks

Premium class is the most prioritized service class in the differentiated service network model. Due to this high priority, the global treatment of the premium traffic strongly affects the low priority classes. In order to reduce this inter-class effect, the routing algorithm used to make the premium paths must minimize the premium load over the network links. This problem, known as optimal premium routing (OPR), is NP-hard. Hence, heuristic algorithms are needed to solve it. All previous works on OPR try to find only one path for the premium traffic between every pair of nodes. Thus, they are applicable merely under low premium loads and as the traffic load increases, they result in high premium congestion in the network. In this paper, we present a multipath scheme to handle OPR problem and propose a distributed routing solution, called multipath premium routing (MPR), to overcome inefficiency of single path routing algorithms. Simulation results shows that MPR elegantly distributes the premium traffic over the whole network and performs better especially in complex and highly-loaded networks.