Design And Implementation Of Network Proxy System Based On QUIC Protocol

With the rapid development of Internet services,massive amounts of metadata between clusters of different data centers need to be synchronized frequently,which requires high-speed and stable network connection for cross-datacenter transmission.In the case of persistent network congestion,the TCP protocol-based services are affected and cannot maintain the available transmission rate.For the problem of single line network failure to communicate,how to ensure stable and high-speed transmission of network links between different data centers at low cost becomes an important issue to be solved.Proxy the traffic of existing TCP connections and use other protocols for transmission in different data centers is a popular solution today.In the original TCP proxy system,the link failures cannot be detected in time,and the TCP protocol identifies connections by four tuples(source address and port,destination address and port),making it impossible to switch links for connections in the proxy.The existing multi-link transmission protocol cannot meet the demand for timeliness and flexibility.To address this situation,developing with the stateless UDP protocol can be performed to achieve orderly and reliable data transmission in the user state,monitor the network link through the multi-link switching algorithm,and switch to the backup link for data transmission when the link fails continuously.In this thesis,the single-link QUIC protocol based on UDP protocol will be modified to make it meet the current usage scenario of multi-link transmission,and the main work of this thesis is as follows:(1)Analyzes the shortcomings of the original TCP proxy system and proposes a multi-link switching detection algorithm Cubic-MP based on Cubic congestion control algorithm and QUIC protocol packet loss detection algorithm.Under the continuous network fault environment,this algorithm makes timely continuous congestion judgment according to the timeout threshold judgment algorithm and the retransmission queue detection algorithm.Through the connection migration algorithm and the initial window prediction algorithm,it also ensures the stability of the link transmission rate.(2)Based on the proposed Cubic-MP multi-link switching algorithm,a cross-datacenter multilink proxy system and related tools are designed and implemented.The proxy system provides system configuration module,proxy program access module,cross-datacenter transmission and link switching,system monitoring and so on.,to meet the requirement of maintaining high-speed and stable transmission of the connection in the case of continuous network failure of the main link.(3)Design and build a test platform to test and verify the implemented multi-link proxy system.By accessing different proxy programs and simulating the network environment,the stability of the transmission rate of the proxy system under the continuous network failure environment is compared and tested.After verifying the correctness and security of the proxy system,the test platform is used to simulate multiple packet loss failure scenarios on the main link,and the transmission rate is used as a measurement index to simulate and test the proxy transmission under real scenarios to verify the availability of the proxy system.In summary,the multi-link switching algorithm Cubic-MP for QUIC protocol proposed in this thesis can be successfully applied to multi-link transmission scenarios,and the multi-link transmission proxy system designed based on this algorithm proves its effectiveness in experimental simulation scenarios.