Rethinking IP Core Networks

The Internet core today is completely based on IP routers. Circuits are only used to provide static point-to-point optical links between routers. As others have recognized, current practice makes it hard to take advantage of very high-speed, low-power optical circuit switches in the core. Despite many proposals to mix packet switching with dynamic circuit switching, none have taken hold. In these times of rapidly increasing traffic, and rapidly decreasing profits for ISPs, it is time to rethink how backbones are built. In this paper, we propose to replace the largest backbone routers with much cheaper hybrid packet-optical switches in a fully meshed IP core. We take advantage of new control planes for software-defined networks to control the packet and circuit networks from a single vantage point. To demonstrate the enormous potential cost savings, we present a detailed analysis of the capital expenditure and show how our approach offers 60% cost savings for typical backbone operators.