OPN08-04: Traffic Routing in a Multi-Layer Optical Network Considering Rerouting and Grooming Strategies

Abstract

Most of the studies dealing with dynamic lightpath establishment (DLE) consider a single type of traffic demand. These demands are in general generated randomly without any information about their life duration. In this paper, one considers for DLE a mix of preplanned traffic and of random traffic. Preplanned traffic corresponds for instance to optical virtual private networks (OVPN). Two approaches for the acceptance of random traffic demands are compared. The first approach consists in evaluating the availability of the required resources only at the instant of arrival of the random demand. The second approach consists in accepting the new random demand only if sufficient resources are available over a given period of time Delta. This time limited reservation imposes to consider at call setup preplanned resources over the period Delta. Indeed, such resources cannot be used by a random demand. The life duration of a random demand being unknown, either its extinction date occurs during the period Delta, or later. In this last case, a rerouting procedure may be necessary to enable the random demand survivability. In summary, the originality of our approach consists in providing a time-limited guaranteed service to random traffic demands instead of a pure best effort service, as it is the case in general.