Lightweight User Space Network Communication Design And Implementation

With the evolution of wireless communication technology,applications that require high-speed data transmission have been developed rapidly.These applications and massive terminals give great challenges to the network processing capability of radio access network equipment and server.However,the traditional network stack doesn't consider the massive communication requirement at the beginning of the design and cannot meet such high-speed and low-latency performance requirement.By analyzing the whole process of traditional network stack,the performance bottleneck is identified,and a new architecture is proposed,which could achieve high-performance network communication by cooperating of user-space network system and traditional kernel-space protocol stack.Then a prototype is implemented and used to verify the performance.The main work of this thesis is:(1)Traditional network protocol stack is analyzed,as well as existing problems,and related improvement schemes.A lightweight user space network communication system is proposed,which uses both of high efficiency of user-space protocol stack and stability of traditional kernel-space protocol stack.(2)Switching system is involved,which parses packet protocol headers to generate packet meta data,and meta data of packet is used to match switching configuration and distributed instead of whole packet.Overhead of large amounts of data copies is avoided.All configuration is preconfigured by control plane without dynamic learning and connection setup overhead is avoided.(3)Control plane service is abstracted to make address exchange,do configuration and status detection,it reduces connection setup overhead in data plane,improves communication efficiency.Service-based communication model is introduced,which decouples application service address from communication protocols.(4)Inter-communication between user space stack application and kernel stack applications.There are different address spaces between user space stack and kernel stack,and transparence of user space stack need be kept for kernel stack.ARP procedure and fake service address is used when communication between hosts,and application proxy and DNAT is used for intra host communication.(5)The software architecture of prototype is introduced in detail,then function and performance test are done.Compared with the traditional protocol stack,the user space protocol stack designed in this thesis has significantly performance improvement.The data rate is about 11 times of the original system and the communication delay is 1/6 of the original system when the packet size is 64 bytes.The new lightweight user space network communication system not only maximizes the efficiency of the user space protocol stack,but also uses the complete functions of the kernel protocol stack to reduce the development and maintenance costs.Through the cooperation of user space protocol stack and kernel space protocol stack it achieved high performance with low cost,it is valuable to promote to use it.