HOBRP: A hardware optimized packet scheduler that provides tunable end-to-end delay bound

A packet scheduler is a primary component of the improved quality of service (QoS) model for today's Internet. Although many fair packet schedulers have been proposed through theoretical consideration, practical high-speed packet schedulers remain elementary. The disparity arises because existent schedulers either lack of necessary QoS guarantee or have an unacceptable cost of computation and storage. In this paper, we propose a simple and efficient packet scheduler called hardware optimized bit reversal permutation (HOBRP) based scheduler. Besides some common merits including low time- and space-complexity, bounded end-to-end delay guarantee and constant fairness index that many well-known schedulers have already owned, our HOBRP still possesses two additional features: One is that the end-to-end delay bound of HOBRP is tunable, which makes itself flexible enough to provide different levels of delay bounds for diverse types of application flows. The other is that all the operations and structures used by HOBRP are very simple and easy to be pipelined and paralleled, which benefits an intuitive high-speed hardware design scheme.