Optimizing multi-layered networks towards a transparently optical internet

Data transported on the Internet is handled by various technologies at different layers. The move towards an optically transparent internet will accelerate when it is justified by the cost structure of the various technologies. In this paper we describe a unified optimization framework for multiple technologies that interwork together based on the following assumptions: (i) every layer is associated with a unique technology, (ii) traffic can be modeled as a Poisson stream of flows, (iii) a flow will be served by a layer (technology) on a least-cost basis. This way traffic is split between the layers and if, under a given cost structure, a layer (e.g. IP) is found to have no "customers" (flows) because it is too costly relative to other layers (e.g. WDM), it will be excluded. In addition to technology choices we also optimize link dimensioning and virtual topology.