Configuring Traffic Grooming VPλNs

A VPλN is an optical virtual private network (oVPN) built of wavelength paths within a multihop wavelength routing (WR) dense wavelength division multiplexing (DWDM) network. An efficient and general graph-theoretic model (the wavelength-graph (WG)) has been proposed along with an integer linear programming (ILP) formulation of setting up VPλNs with given traffic requirements over a given WR-DWDM network with two protection scenarios. Here, we have exploited the advantages of traffic grooming, i.e., numerous traffic streams of a VPN can share a wavelength path. We have also generalized the model for setting up VPNs over a WR-DWDM system where multiple VPNs can share a single wavelength path. The objective of the optimization is in all cases to reduce resource usage at upper (electrical) layers (i.e., to reduce the load of the virtual routers), subject to constrained amount of capacity of each wavelength channel and limited number of wavelengths. Here, we propose and compare three basic methods for configuring oVPNs and investigate various parameter settings.