Optimal virtual topology design using bus-label switched paths

Despite an observable trend in reducing the number of layers in core and metropolitan area networks, still the optimal design of multi-layer networks (like IP over WDM) remains an important issue as a means to reduce CAPEX and OPEX. In multi-layer networks, usually a connection oriented transport network (like WDM) is used to deploy a layout for optimal transport of traffic. In today's networks, the layouts are based on point to point LSPs. We will show here that by using a novel concept named bus-LSPs, we can achieve some significant savings for the operator, both in terms of CAPEX and OPEX. We also introduce a heuristic algorithm to design optimal layouts, and provide a quantitative evaluation