On the design of QoS-based virtual private networks over IP/WDM networks

In this paper, we study the problem of designing logical topology for virtual private networks (VPN) over IP/WDM networks considering different QoS requirements. For a given network physical topology and long-term traffic pattern, design of delay-based logical topology can be formulated as a linear problem, a NP-hard problem, which is computationally intractable for large size of networks. So, a heuristic algorithm is presented to address the problems of routing and wavelength assignment. Simulation results show that the developed scheme performs well in terms of QoS performance metrics such as the lightpath hop length and the network maximal link load.