A rate regulating traffic conditioner for supporting TCP over Diffserv

The ever-growing usage of the Internet and the popularity of multimedia applications result in a need to extend its simple best-effort service model. Differentiated Services (Diffserv) is a promising architecture for supporting a wide range of network services over the Internet. While scalable and flexible, Diffserv must still overcome several challenges including providing per-flow service guarantees and fairness. A critical problem is the difficulty faced by TCP flows in achieving their guaranteed or fair-share rates, especially when competing with flows that do not support congestion control mechanisms, such as UDP. In this paper, we present a traffic conditioner based on Rate Regulation via Early Adaptive Detection (READ). READ uses knowledge of TCP congestion control behavior to proactively regulate flow throughput in order to achieve the desired rate. Our simulation results demonstrate READ's effectiveness in providing TCP flows with their guaranteed or fair share rates. Its adaptive early detection mechanism leads to highly predictable TCP flow behavior, even under dynamic load environments with high priority traffic and competing UDP flows. (C) 2000 Published by Elsevier Science B.V.