Design And Implement A Docker-based Online Lab Platform For Learning Computer Networks

"new engineering" actively advocates that the training of engineering talents should strengthen practical teaching.However,in the traditional practical teaching of communication engineering courses such as computer network,it is difficult to adapt to the practical teaching needs of the rapid evolution of computer network technology because of the high cost and slow updating of experimental equipment.In recent years,virtual simulation experiment has been gradually applied to computer network experiment teaching,but the computer network simulator represented by ns-3 also has some problems,such as high computing resource occupation,high entry threshold and complicated software environment configuration.COVID-19 has further promoted online learning and blended teaching,while traditional experimental teaching cannot support new teaching models.This thesis fully investigated the core teaching needs of teachers and students in a computer network course of a university.This thesis designed and implemented a Docker-based Online Lab Platform for Learning Computer Networks,which called ns3lab:1)Based on Redis message queue,WebSocket and distributed queue,a distributed queuing scheduling module is designed,and the resource servers is formed into a computing cluster to realize the dynamic expansion of computing resources,support emergent experimental task requirements,and effectively improve the ability of concurrent simulation experiment of the system.2)This thesis used Docker to encapsulate ns-3 and it’s running environment.A Web experiment platform with code editor and virtual terminal was designed and implemented.Advanced functions such as user code cache,experiment background running,and off-line recovery are designed to provide students with an online experiment environment without configuration.4)Design an experimental teaching management system including mirror management,class and experiment management,student experiment scoring and user management modules,effectively support teachers to realize the experimental teaching informationization.Ns3lab adopts the development mode of frontend and backend separation.Vue2 framework and Python Tornado framework are adopted for the frontend system and the backend system respectivly.In this thesis,the function and performance of ns31ab are deeply tested.Based on more than 40 test cases,this thesis verifies that the modules of user management,class and experiment management and online experiment all meet the design requirements.In this thesis,ns31ab is deployed on Tencent cloud platform to conduct network performance test on the actual public network environment.The experimental results show that the interface request delay is generally less than 110 ms and all less than 600 ms under the condition of 300 concurrency,which meets the teaching needs.When two common hosts are used to form a distributed cluster and the number of concurrent experiments is 25,the average execution time of the simulation experiment is 14 s,and the maximum execution time is 26 s,which is short and meets the requirements of concurrent experiments based on the class.Only few resources could meet the needs of concurrent experiments in classrooms.The ns3lab experimental platform developed in this thesis effectively reduces the construction cost of experimental platform and experimental proj ect,reduces the learning threshold for students to conduct network simulation experiments,and provides teachers with efficient and easy-to-use experimental teaching AIDS.The system has been put into experimental teaching practice of computer network.