Flow Protecting And Scheduling Algorithm Based On SDN For Data Center Network

With the rapid development of the Internet and the emergence of emerging technologies,the traffic in data center network(DCN)shows an explosive growth.This growth has brought tremendous challenges to traditional traffic protection and scheduling.The traditional traffic protection scheme lacks the global network topology information as data support,which easily leads to the local optimal solution of the network.And the traffic scheduling is a research which conducted on the basis of traffic protection and part of the traffic scheduling is easy to cause the local link congestion and inability to fully utilize the rich link resources in the network.Therefore,researchers have proposed some methods to solve the above problems by combining Software Defined Networking(SDN)and data center network.The main research of this paper is as follows:1.Existing traffic protection schemes fail to do analysis from the perspectives of different traffic requirements and users.In the meantime,link state information of the network also changes in real time and links are prone to failure.Therefore,the loss of data packets is easy to be caused,which will affect user experience.In response to this problem,this paper proposes a traffic type based failure recovery(FT-FR)method.First,the traffic in the network is divided into three types.And then,the customized requirements of different traffic are introduced.Finally,the differentiated traffic protection strategies are designed for different traffic.Simulation results show that,compared to backup-resource based failure recovery and fast recovery approach,FT-FR saves 27.2% and 37.5% of switch traffic table entry consumption,and link failure recovery latency decreases by 11.4% and 15.3%,respectively.The average throughput of the network has not been changed.2.The backup path planned by the traffic protection strategy is the input parameter of the traffic scheduling strategy.The traffic scheduling operation can be performed only after the backup path is known.In the traffic scheduling operation,because the loop is easily formed between the resource node and the operation node,it is difficult to plan appropriate traffic scheduling operation sequences,thereby prolonging the traffic scheduling time and resulting in the loss of the data packet.To solve this problem,this paper proposes a traffic rate limit(Rate-Limit)scheduling method.First of all,a R-O map is generated based on the current state of the network,the target state and the constraint conditions.Thereafter,what kind of traffic scheduling strategy will be employed is determined by checking whether a loop is formed in the R-O figure.The simulation results show that,in terms of traffic scheduling speed,the proposed scheme increased by 24.7% and 19.6% compared with Equal-Cost Multi-Path(ECMP)and PureSDN,respectively.In addition,the network link bandwidth utilization ratio increased by 21.5% and 5.07%,and the packet loss rate decreases by 18.4 % and 4.7% compared to those two methods.