On-line resources allocation for ATM networks with rerouting

We have developed an application for France Telecom R&D, which takes place in an ATM (Asynchronous Transfer Mode) network administration context. The problem consists in planning demands of connection over a period of one year. A new demand is accepted if both bandwidth requirements and quality of service are satisfied. The acceptance or the reject of a demand must be decided within at most one minute. First, we look for a route satisfying the demand. In case of failure, we try to reroute some already accepted connections in order to satisfy the new demand. Rerouting has been modeled as a Valued Constraint Satisfaction Problem (VCSP) and solved by VNS/LDS+CP, a hybrid method specifically dedicated to solve VCSPs in anytime contexts. Experiments show that our rerouting enables to plan an average of % of demands that are rejected otherwise.