LSP Setup Arrival Reordering Approach for MPLS-TE Routing

In this paper, we evaluate a solution based on the preemption mechanism so as to improve performances of distributed multi-protocol label switching-traffic engineering (MPLS-TE) path computation, where requests are handled one by one, in an uncoordinated manner without any knowledge of future and other requests. Our solution is motivated by the considerable impact of the tunnel setup order on the network load and blocking probability. If it is not possible to control this order, in return it is possible, in some cases, to reorder requests using the pre-emption function. After evaluating the impact of the tunnel setup order, we study the use of preemption to reorder LSP setup, with various algorithms, including shortest path first (SPF), widest shortest path (WSP) and shortest widest path (SWP). We show that the preemption is well suited to shortest path based algorithms and the performances in terms of blocking rate are significantly improved.