设数据链路层通信的两个站点分别为A 和B，仿真环境利用TCP 协议和Socket 客户端/服务器机制构建两个站点之间的通信。编译、链接之后生成的可执行程序(.exe 文件)为字符界面命令行程序（不是图形界面程序）。可执行程序文件仅有一份，设为datalink.exe，在两个DOS窗口中使用不同的命令行参数启动两个进程，分别仿真站点A和站点B。例如：

启动站点A进程的DOS命令：datalink a

启动站点B进程的DOS命令：datalink b

其中，站点A 以TCP 服务器的身份运行，默认监听TCP 端口59144；站点B 以TCP 客户端身份运行，默认连接127.0.0.1 的TCP 端口59144。-Two sites set up the data link layer communication are A and B, the simulation environment using TCP protocol and Socket client/server mechanism to build communication between the two sites. Compile, then link the resulting executable program (. Exe file) for the character interface command line program (not a graphical interface program). Just copy the executable file, set datalink.exe, line parameters to start two processes use different commands in both DOS window, respectively simulation Site A and Site B. For example: Start Site A process DOS command: datalink a start site B processes the DOS command: datalink b where site A TCP server runs as the default listens on TCP port 59144　Site B runs in TCP client identity, the default connection 127.0.0.1 TCP port 59144.