Research Of Network Congestion Control Algorithm Based On Multi-service QoS

The congestion control and Quality of Service are two closely related research subjects.It is the basis of supplying the QoS to carry out effective congestion control.The traditional TCP congestion control mechanism which is based on end to end is unable to implement effective congestion control to use the transmitted information of the internet,so researchers gradually transfer the research focal point of congestion control to core node router,especially,increase the research to the active queue management algorithm.The objective of the paper to research congestion control algorithm is to achieve the QoS requirement of multiple services of the internet.With the application of internet mushrooming,the internet is to meet the need of real-time requirement also the non-real-time requirement.The corresponding QoS to solve is to simultaneously support multiple types of service and guarantee every service to reach its performance requirement in the internet.The paper analyzes and researches systematically RIO-C algorithm,and reaches a conclusion of having deficiency of unfair in RIO-C by analysis and emulation,then proposes one improved DiffServ Active Queue Management algorithm which is named OPRIO.OPRIO optimizes the computer of the average queue length.OPRIO algorithm adjusts the proportion which low drop priority group queue length to participate in the compute of high drop priority group queue length, by setting a dynamic factor and according to the proportion of the low drop priority group in the whole queue.Then relieves the "hunger" appearance of the high drop priority group.The emulation indicates OPRIO minishes the discrimination to the high drop priority group on achieving the distinction of distinctions ground,and make the different drop priority groups enjoy more justification.At the same time OPRIO algorithm raises availably the output of the internet and the link utilization ratio, makes the internet resource full use.OPRIO algorithm to resolve is impartial service problem of different priority group in Per Host Behave of Assure Forwarding of DiffServ.In fact,In AF model of Diffserv,fair of data stream among PHB is considered.The paper also proposes enhanced OPRIO algorithm which is named EOPRIO algorithm,which guarantees the justification of data stream among PHB by controlling the buffer capacity of different PHB,and strengthens flexibility of system and the QoS.