Performance Evaluation And Fairness Analysis Of Congestion Control Algorithm

With the rapid development of Internet technology,the current network communication environment has become increasingly complex.In the terrestrial Internet,the transmission bandwidth is getting higher and higher,the link structure is more and more complex;in some special networks,such as satellite network,the communication distance farther and farther,the propagation delay is bigger and bigger,which has brought unprecedented challenges to the current TCP transport protocol.In view of this,more congestion control programs have been proposed to make this field a research hotspot.In this paper,a series of common congestion control algorithms(TCP-Reno,TCP-Cubic,TCP-Hybla,TCP-Vegas,TCP-Westwood,TCP-BBR and PCC)are studied theoretically.This paper analyzes the improvement points of these seven algorithms for the traditional congestion control algorithm and the adaptability in spatial communication.On the basis of theoretical analysis,seven kinds of congestion control algorithms are evaluated by constructing simulation scenarios of ground and space communication.For TCP-based protocols,our main performance parameters are the congestion window,slow start threshold and throughput of the sender,for the PCC protocol,this paper focuses on the transmission rate and throughput of the sender.We uses TC and Netem to dynamically adjust the channel parameters of the simulation link.The channel parameters include round trip delay,channel bandwidth and channel packet loss rate.The round-trip delay is set according to the ground-based network,low-orbit satellite network and GEO backbone network.As a result of the multi-round simulation test for each channel parameter combination,in order to aviod mistakes in setting the parameters of sender and channel,so the simulation work mainly through programming automatic simulation test tools to dynamically change the test scene.After the simulation work is completed,the performance of the algorithm in different communication scenarios,especially in the space communication scene,is analyzed according to the performance parameters of each algorithm,thoes provide an important reference for the algorithm selection in space communication.At the same time,the new congestion control algorithm is proposed,but more machine protocol stack is built on the traditional congestion control algorithm.Therefore,it is very important for the new algorithm to maintain good fairness with the traditional congestion control algorithm,The transmission fairness of the congestion control algorithm not only affects whether the existing communication nodes can effectively utilize the link bandwidth,but also influence the popularization of the new algorithm.In this paper,we test the evaluation of the fairness of the new algorithm and TCP-Reno algorithm so that we can have a clearer understanding of these new algorithms.