A Hierarchical Multiobjective Routing Model for MPLS Networks with Two Service Classes

This work presents a model for multiobjective routing in MPLS networks formulated within a hierarchical network-wide optimization framework, with two classes of services, namely QoS and Best Effort (BE) services. The routing model uses alternative routing and hierarchical optimization with two optimization levels, including fairness objectives. Another feature of the model is the use of an approximate stochastic representation of the traffic flows in the network, based on the concept of effective bandwidth. The theoretical foundations of a heuristic strategy for finding “good” compromise solutions to the very complex bi-level routing optimization problem, based on a conjecture concerning the definition of marginal implied costs for QoS flows and BE flows, will be described. The main features of a first version of this heuristic based on a bi-objective shortest path model and some preliminary results for a benchmark network will also be revealed. José Craveirinha e-mail: [email protected] · Rita Girão-Silva e-mail: [email protected] Department of Electrical Engineering Science and Computers of the University of Coimbra Pólo II, Pinhal de Marrocos, P-3030-290 Coimbra, Portugal Institute of Computers and Systems Engineering of Coimbra (INESC-Coimbra) R. Antero de Quental, 199, P-3000-033 Coimbra, Portugal João Clímaco Faculty of Economics of the University of Coimbra Av. Dias da Silva, 165, P-3004-512 Coimbra, Portugal Institute of Computers and Systems Engineering of Coimbra (INESC-Coimbra) R. Antero de Quental, 199, P-3000-033 Coimbra, Portugal e-mail: [email protected] Lúcia Martins Department of Electrical Engineering Science and Computers of the University of Coimbra Pólo II, Pinhal de Marrocos, P-3030-290 Coimbra, Portugal Institute of Computers and Systems Engineering of Coimbra (INESC-Coimbra) R. Antero de Quental, 199, P-3000-033 Coimbra, Portugal e-mail: [email protected] Work partially supported by programme POSI of the EC programme cosponsored by FEDER and national funds.