Abstract: In order to guarantee the quantity of flow medium traffic delivered in the network, congestion control strategy is adopted in flow medium traffic. According to the delay sensitivity of flow medium data, this paper proposed a novel congestion control for multimedia transmission in networks known as Accumulative Delay Fuzzy Congestion Control (ADFCC). ADFCC improves the QoS of multimedia stream in network by detecting and discarding these packets that accumulated delay exceeds multimedia stream's delay tolerance so as to maintain high bandwidth utilization. All kinds of packets were firstly classified into queues according to their own priorities which calculated by accumulative delay. Then the buffer state was divided into three phases, including normal, congestion avoidance, and congestion according to their buffer usage ratio. hhe three phases arc crossover each other because of their fuzziness. hhen by combining the whole congestion control,with the part congestion control,the fuzzy congestion control algorithm was carried out. Simulation results show that the proposed scheme can effectively reduce the average received packet delay than that of using traditional congestion control algorithm. Moreover, it is suitable to be used in the ever-changing network environment and can improve utilization of the network resources.

Key words: Flow medium,Congestion control,Dynamic queue management,Accumulative traffic delay