An Effective Feedback Control Mechanism for DiffServ Architecture

As a scalable QoS (Quality of Service) architecture, DiffServ(Differentiated Service) mainly consists of two components: trafficconditioning at the edge of the DiffServ domain and simple packetforwarding inside the DiffServ domain. DiffServ has many advantages such asflexibility, scalability and simplicity. But when providing AF (AssuredForwarding) services, DiffServ has some problems such as unfairnessamong aggregated flows or among micro-flows belonging to an aggregatedflow. In this paper, a feedback mechanism for AF aggregatedflows is proposed to solve this problem. Simulation results show that thismechanism does improve the performance of DiffServ. First, it canimprove the fairness among aggregated flows and make DiffServ morefriendly toward TCP (Transmission Control Protocol) flows. Second, itcan decrease the buffer requirements at the congested router and thusobtain lower delay and packet loss rate. Third, it also keeps almost thesame link utility as in normal DiffServ. Finally, it issimple and easy to be implemented.