The k-splittable flow model and a heuristic algorithm for minimizing congestion in the MPLS networks

In the multiple protocol label-switched (MPLS) networks, the commodities (packets) are transmitted by the label-switched paths (LSPs). For the sake of reducing the total cost and strengthening the central management, the MPLS networks restrict the number of paths that a commodity can use. For maintaining the quality of service (QoS) of the users, the demand of each commodity must be satisfied. Under the above conditions, some links of the network may be too much loaded, which affecting the performance of the whole network drastically. For this problem, we first establish two mathematical models, namely the arc-path and arc-flow model. Second, we design a heuristic algorithm which quickly finds paths for each commodity, and then allocate demands for them. In the last, the computational results are tested on a set of medium-sized instances to show the effectiveness of our approach.