A note on fair queueing and best-effort service in the Internet

Providing fair and stable service to competing best-effort flows over a bottleneck router/link pair is a major challenge. Recently there is growing interest in providing isolation and bandwidth guarantees to TCP flows by using fair queueing. We investigate the application of fair queueing first to provide service fairness and later to provide service discrimination. We argue that it is acceptable to use a low work complexity version of fair queueing, such as Deficit Round Robin, instead of other highly complex implementations. We show, through simulations, that Deficit Round Robin provides almost perfect isolation between nonresponsive flows compared to FIFO. In the sequel we present simulation results comparing TCP flows competing for a bottleneck link with FIFO and with DRR.