远程安全连接的例子，类似于隧道连接技术，网络安全编程基础-connecting example, similar to the tunnel linking technology, network security based programming

防火墙技术是建立在现代通信网络技术和信息安全技术基础上的应用性安全技术，越来越多地应用于专用网络与公用网络的互联环境之中。-Firewall technology is a modern communication network technology and information security technology based on the application of security technology, more and more used in private network