| Along with the development of modern informationized society,the kind of Internet applications increase,network bandwidth and quality of service requirements of users also increase.Lightpaths which provided by optical network with a large capacity,high reliability and high QoS features,making it be an effective solution to transmit Internet data.In the networks,some high-priority users need high bandwidth and quality of service,operators will provide them with a dedicated lightpath.And in order to ensure its quality of service,the lightpath bandwidth is usually overprovided,which makes the lightpath bandwidth utilization become low.Although the control plane of optical circuit switch network support application-driven(re)configurability of bandwidth resources.It will lead to the transmission of traffic flow interruption,affecting the quality of service.For ordinary Internet users whose bandwidth and quality of service requirements are relatively low,operators will transfer many users traffic by statistical multiplexing,but when these users simultaneously transfer large amounts of data,there may be congestion in lightpath,that delay and packet loss will occur,result in low-priority users' quality of service reduce.Software defined network is a centralized control network architecture,the controller can obtain network status information of all links and control the transmission path of flows by configuration flow table in the switches.This paper propose a flow aggregation and migration scheme based on real-time lightpath load.The SDN controller can monitor the bandwidth usage of lightpath in real-time,aggregate low-priority flows into a lightpath which used by high-priority flow to improve the utilization of the lightpath,and migrate the low-priority flow from the lightpath when the lightpath bandwidth used up to ensure transmission quality.This paper built a prototype system to verify the function of each module,proved the feasibility of the program.And analysis our scheme performance by a simulation program.Our scheme on one hand can improve the bandwidth utilization of lightpath and increase network throughput without affecting the transmission quality high-priority flow.On another hand,our scheme can reduce the load of lightpath for low-priority flow to reduce congestion occurs,and improve the quality of service. |
