Performance evaluation of router switching fabrics

Switching fabrics with distributed control for scalable routers have been proposed recently. Such a fabric consists of small routing units (RU's) interconnected by multistage-based connecting components (CC's) according to grid structures, thereby referred to as a grid-oriented, Multistage-connected RU's, dubbed GMR, and is a direct interconnect with distributed routing. Performance of GMR is evaluated analytically and by simulation, with the packet mean latency being a key performance measure of interest. Under simplified assumptions and uniform traffic distributions, our analytic results are found to be very close to the simulation results (usually within 3% of each other) for a wide range of sizes, providing confidence to our simulation tool. Our simulation study demonstrates that GMR can deliver packets to their destination ports effectively in practical settings even when many ports run at a high-speed rate of 40 Gbps and non-uniform traffic exists. GMR is readily applicable to scalable routers with large numbers of high-speed ports.