Design of traffic grooming optical virtual private networks obeying physical limitations

Physical impairments in both metropolitan optical networks (MON) and long haul optical networks (LHON) often influence the signal quality, therefore a proper routing decision is needed. In this paper we investigate how to design traffic grooming optical virtual private networks (oVPN), over WDM (CWDM or DWDM) networks, while obeying the properties of the physical layer. Although we obtain these limiting properties using simulations, actual measurements can be used as well. Optimization was achieved by integer linear programming (ILP) (T. Cinkler, February 2001), where the physical limitations are represented using a set of new variables and constraints. Since the problem is NP hard, we decompose it using heuristics into multiple, less complex, sub-problems. The proposed method is illustrated in a case study.