A Queueing-based Performance Model Of Packet Forwarding In Software Defined Network

At present,the Internet combines with the depth of each industry,the network continues to expand,too many complex protocols and a variety of configurations,making the network more and more crowded.As a new network paradigm,Software Defined Networking(SDN)decouples control logic from data forwarding devices resulting in logically centralized controllers.It provides a new solution to improve network transmission efficiency,improve application performance,and reduce deployment costs.However,logically centralized control plane is prone to arise performance bottlenecks in SDN,and it is necessary to understand its performance characteristics.Compared with the performance model for the hypothetical SDN network scenario other scholars proposed,we propose the performance model of packet forwarding more accurately based on queueing theory for the specific SDN deployments.The studies of this paper are as follows:(1)For SDN deployments in wide area network,we investigate into Packet-in message arrival process of controller cluster and packet arrival process of switches.As a further step,the two queueing models M/M/nlm and MIM/1/m are respectively applied to characterize the processing performance of messages and packets.On this basis,we build a performance model of packet forwarding in SD-WAN,and derive its average packet forwarding time.Finally,our proposed performance model of controller cluster is evaluated by experiments with the measurement tool OFsuite_Performance.Experimental results indicate that the estimated delays of our proposed model are more approximate to measured delays than those of other existing models.Lastly,we give minimum deployment requirements of controller clusters under different network scales,which provides references for SD-WAN deployments.(2)For SDN deployments in data center network,we investigate into Packet-in message arrival process of controller cluster and packet arrival process of switches.As a further step,the two queueing models L/M/n and L/M/1 are respectively applied to characterize the processing performance of messages and packets.On this basis,we build a performance model of packet forwarding in SDDCN,and derive its average packet forwarding time.Finally,our proposed performance model of controller cluster is evaluated by experiments with the measurement tool OFsuite_Performance.Experimental results indicate that the estimated delays of our proposed model are more approximate to measured delays than those of other existing models.Lastly,we give optimal deployment requirements of controller clusters under different network scales,which provides references for SDDCN deployments.