一种基于容器的低轨卫星网络协议测试床  

A Docker-Based LEO Satellite Network Testbed

作　　者：潘恬 李星辰 薛文浩 边子政 黄韬[1] 刘韵洁[1] PAN Tian;LI Xing-Chen;XUE Wen-Hao;BIAN Zi-Zheng;HUANG Tao;LIU Yun-Jie(State Key Laboratory of Networking and Switching Technology,Beijing University of Posts and Telecommunications,Beijing 100876)

机构地区：[1]北京邮电大学网络与交换技术国家重点实验室,北京100876

出　　处：《计算机学报》2022年第9期2029-2046,共18页Chinese Journal of Computers

基　　金：国家重点研发计划(2019YFB1802600);国家自然科学基金青年科学基金(61702049);中央高校基本科研业务费资助.

摘　　要：近年来,以SpaceX为代表的商业航天公司提出了多个超大规模低轨卫星星座组网计划.卫星路由器是构建卫星互联网的关键基础设施.考虑到卫星路由器高昂的研制和发射成本,在卫星发射之前预先在地面上做好卫星星座的组网仿真和半实物接入验证具有重要意义.相比传统地面网络的仿真验证,卫星星座组网仿真面临高动态拓扑、超大组网规模、真实流量承载仿真以及半实物接入验证等需求和挑战.目前已知的地面网络通用仿真工具(如QualNet、NS2/NS3、OPNET、Mininet)均无法同时满足上述仿真要求,实现对超大规模动态卫星网络节点的真实协议栈验证.我们针对以上需求,吸收离散事件模拟和虚拟化仿真的思想,以容器为载体,设计并实现了一种低轨卫星网络协议测试床.在控制平面,系统基于卫星星座的数学建模,在内部时钟节拍驱动下生成链路通断的离散事件,精确描述星座拓扑的规律变化.在数据平面,系统使用Docker容器实现卫星和地面终端,使用Linux虚拟网络设备实现星间和星地链路,并基于隧道协议实现系统的分布式部署和半实物仿真,使其具备优秀的横向扩容能力,从而解决超大组网规模下的单机仿真性能瓶颈.为了充分挖掘多核处理器的计算潜力,系统基于多线程对仿真过程中产生的大量离散仿真事件进行高并发调度.实验结果显示,在多核处理器主机上,该仿真测试床能够同时运行3276个网络节点并承载1.6 Gbps的真实流量.与单线程实现比较,多线程的任务并发处理机制使得CPU利用率提高了45%,仿真场景创建时间缩短了56%.In recent years,commercial space companies represented by SpaceX have proposed numerous mega-scale low-earth-orbit(LEO)satellite constellation networking plans.Satellite routers are the key infrastructure for the satellite Internet.As the manufacturing and launching costs of satellite routers are considerably high,it is necessary to conduct large-scale network emulation as well as hardware-in-loop verification on the ground before launching the satellites into space.Compared with traditional network simulation/emulation solutions,the ground emulation of mega-scale satellite constellation networks has the requirements and challenges of highly dynamic topologies,mega-scale networks,real traffic emulation,and hardware-in-loop verification.At present,existing ground network simulation/emulation tools(such as QualNet,NS2/NS3,OPNET,Mininet)cannot meet the above requirements simultaneously to verify the real protocol stack of mega-scale dynamic satellite networks.To address the above requirements,we design and implement a container-based LEO satellite network testbed by integrating discrete event simulation technology and virtualization-based emulation technology.In the control plane,the system is based on mathematical modeling of the satellite constellation and produces discrete events of the satellite link on and off under the drive of an internal clock,which precisely reflects the regular topology changes of the network.In the data plane,the system leverages Docker containers to implement the satellite and ground nodes,and leverages Linux virtual network devices to implement the inter-satellite and satellite-ground links.The system enables distributed deployment and hardware-in-loop emulation based on the tunneling protocol,making the system have good horizontal expansion capabilities to break the performance bottleneck of single-host emulation.To fully exploit the computing capability of the multi-core processors,the system has developed a concurrent task scheduling mechanism based on multithreading for performant s

关 键 词：低轨卫星网络 容器 虚拟网络设备 拓扑变化 多线程 分布式部署 半实物仿真 数字孪生 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]