An improved algorithm of DRR combining with traffic shaper

摘要

The common round-robin algorithm schedules all the queues whose bandwidths fairness are limited because of the unfixed packet size. The DRR gives each queue an quota and a counter which solves the problem of the bandwidths fairness. The defect is that the output is not so smoothed. So in this paper, we used a traffic shaper based on network calculus which could smooth the output traffic. The first topic was about the elementary network calculus. And the second topic was shaper with finite buffer. We got the number of packets discarded, buffering zone, delay and the max delay through network calculus. In the third topic, we introduced the token buffer filter in detail. Combining with the DRR algorithm, we performed the computer simulation and the results shows that this improved method can smooth the output information and then improves the quality of service.