OS support for general-purpose routers

This paper argues that there is a need for routers to move from being closed, special-purpose network devices to being open, general-purpose computing/communication systems. The central challenge in making this shift is to simultaneously support increasing complex forwarding logic and high performance, while using commercial hardware components and open operating systems. This paper introduces the hardware and software architecture for such a general-purpose router. The architecture includes two key innovations. First, it better integrates the router's switching capacity and compute cycles. We expect this to result in significantly better scaling properties, and an order of magnitude improvement in performance for packets that require only minimum processing cycles. Second, the architecture supports a hierarchy of forwarding paths, ranging from fast/fixed paths implemented entirely in hardware to slow/programmable paths implemented entirely in software, but also including intermediate paths that exploit the improved integration of cycles and switching.