Research And Implementation On Congestion Control In Software-Defined Network For Datacenters

Because of its features of centralized control and providing open programmable interface,the software-defined network simplifies the procedure of network configuration,makes resource allocated and utilized more flexible and scalable,and has been widely used in data centers.However,due to the burst and random nature of traffic,there are network congestions in data centers,which causes quality of service provided by the network not guaranteed.To deal with network congestion in data centers,this paper studies and proposes a technology of congestion control in SDN which would forward the elephant flows on the congested link to other links with low bandwidth.This paper proposes a technology of routing by probability which would forward the elephant flows to other paths and select path in a random way based on the probalility counted based on Multi-Logit Model.This paper designs and implements a congestion control system in software-defined network.The main contents of this paper are as follows:1)To control the network congestion in data centers,this paper proposes a technology of congestion control in software-defined network.This technology would monitor the links periodically and when congestion occurs,it would forward the elephant flows to other links.2)At present,popular routing algorithms tend to aggregate multiple flows to the same link in the network,which would result in new congestion.This paper proposes a technology of routing by probability,which selects path in a random way based on probalility counted based on Multi-Logit Model and reduces the frequency of multiple flows aggregated.3)This paper designs and implements a congestion control system in software-defined network,which includes the topology management module,the network status information module,the congestion monitoring module,the elephant flow detection module and the routing module,and then takes experiments to test the performance of this system.It's verified that when congestion occurs,the system can improve the throughput and reduce the packet loss rate compared to GFF and OIFF.