A multilayer solution for path provisioning in new-generation optical/MPLS networks

This paper proposes an offline solution for global path provisioning in new-generation optical networks based on the generalized multiprotocol label switching (GMPLS) paradigm. This solution is based on a multilayer approach, which involves both the optical and the electrical layers and optimizes the network configuration and traffic routing. The proposed global provisioning solution can be easily combined with dynamic routing solutions, providing the network with the possibility of reacting promptly to traffic changes. Data flows are assumed to be structured into label switched paths (LSPs), which represent the connection in a GMPLS-based network, at any hierarchical level. The global provisioning issue is a difficult optimization problem. As a solution, we propose a new heuristic algorithm based on the shortest path computation and a mathematical programming approach, which makes use of the optimization solver CPLEX. A large computational study shows the effectiveness of the former, in terms of quality of the solutions. The advantages of the multilayer provisioning strategy are analyzed in a relevant case study by evaluating the network congestion.