Research On The Congestion Control Algorithm Based On DiffServ

The issue of Network Congestion exists throughout development of the Network technology, which is also one of its limiting factors. The Network Congestion happens due to the imbalanced allocation of the network resources and the flows. It will significantly decrease the network throughputs and increase the time of the End-to-End delay. In that case, the bandwidth is inadequate for each service flow which directly impacts the quality of service (QoS). Therefore, it has become a research hotspot that how we can manage the network congestion control and sustain the QoS in the presence of network congestion. The requirements of QoS are getting higher because of the network expansion and the advent of audios and videos with high real-time requirements. In Differentiated Service Model, the Packet Scheduling technique is a core of guaranteeing the QoS. It can also be used to control the Network Congestion and ensure the fairness of the bandwidth allocation and therefore becomes the focusing point of this thesis.Round-robin scheduling is a common packet scheduling policy, and the traditional round-robin scheduling WRR has a fairness problem of bandwidth allocation. Therefore it is not possible to be applied in the variable-length packet network. This paper proposed an improved algorithm, based on the WRR, named CWRR (Changeable Weighted Round Robin). In CWRR, the weight of the CWRR varies adaptively depending on the average packet length, to make it more adaptable to the network environment. Additionally, through the simulation analyses of the performance of the new algorithm with NS2, it is shown that the fairness of CWRR becomes better than that of the WRR .