Virtual-time-based round robin: A hardware-efficient fair scheduling algorithm for high-speed networks

Effective fair scheduling algorithms permit high-speed switches to divide link bandwidth fairly among competing sessions so that they enable each session to satisfy QoS requirements. In this paper we propose a novel fair scheduling algorithm which we call "Virtual-Time-Based Round Robin (VTRR). " It serves packets with the virtual finishing time less than or equal to the current virtual upper bound in each round in a round robin manner Since it is based on the approximated virtual time and on an appropriate architecture, it takes only O(1) processing work per packet, which indicates that VTRR is appropriate for high-speed implementation. Our analysis and simulation experiments demonstrate that it presents the fairness to competing sessions and its performance is close to that of Weighted Fair Queueing (WFQ).