The Research On MPTCP Transmission Optimization Technology In Multipath Network Environment

Today,more and more electronic devices such as smartphones,tablets and laptops are equipped with various interfaces for accessing the Internet,such as 3G,4G,WiFi and IP networks.In order to ensure the robustness,many network devices in computer network have a lot of redundant capacity which has not been used,resulting in some waste.In order to improve the utilization of network resources,multipath transmission technology starts to develop rapidly.The core idea is to share the data flow to multiple links to improve network utilization and reduce the cost of network access equipment.Among multipath transmission technologies,Multipath TCP(MPTCP)protocol has become a research hotspot in recent years.MPTCP protocol is an extension of TCP protocol,allowing multiple subflows to be created and transferring data in parallel in one connection.Many multi-path transport technologies are not compatible with application layer applications,network middle boxes with high commercial costs.However,the MPTCP protocol is compatible with the traditional TCP protocols,network middle boxes without modification of applications.Therefore,it has great promotion prospects.However,there are still many shortcomings in the existing MPTCP protocol.In this paper,we improve MPTCP-based multipath transmission technology from the aspects of congestion control algorithm,packet scheduling algorithm and security.Firstly,we extend TCP congestion control algorithm CDG to MPTCP protocol and present the MP-CDG algorithm,taking into account the bottleneck shared with single TCP flow.This algorithm trade between network throughput and fairness of TCP and can still get higher throughput than the classic MPTCP congestion control algorithm LIA.Double queue-double scoring(DQ-DS)packet scheduling algorithm is proposed to set up two level queue model to ensure that the subflow has a reasonable sending rate,dynamically evaluate the subflows' current performance and give a score.Then selecting the best flow for the packet to transmit,which can reduce the number of packets arriving out of order,and improve the overall throughput.We apply the MPTCP protocol to improve the security in Internet transmission.A secure transmission framework based on MPTCP is proposed.Finally,we add the MPTCP function to the NS-3 network simulation platform and implementing the above MP-CDG algorithm and the DQ-DS algorithm on the NS-3.Compared with the previous algorithm,the verification can indeed achieve certain validity and improve the transmission Throughput.