Virtual Private Network In Application Of Air-defense Alarm System

Civil air defense is an important part of modern territorial air defense, charged with the protection of life and property safety. Air defense alarm control system is part of the main functions of civil air defense projects. In this paper, the existing Air defense alarm remote control system is been studied, and we found some problems in this system. Through in-depth study of VPN, analysing and comparison of a variety of VPN tunneling technology and the characteristics of air desense alarm control system, we proposes a VPN control system of air defense alarm communication network, to achieve the wire control of system and improve the reliability and security of system.This paper gives the three-levels structure of alarm control system framework, the communication network is designed to connect each levels.Preserving the wireless control mode, design of wire communication module in the alarm control terminal. With network communication protocol embedded in microchip, to achieve control terminal connected to the Internet. By implanted programming in the MCU with PPTP, we can set up a client/server VPN network between the VPN server and the terminals, and transmit private information above internet with VPN tunnels.The specific works in this paper including improve the encoding format of the system, assign a new encryption algorithm of communication, and design a Ethernet interface module for the terminal based on C8051MCU and the CP2200ethernet controller. Also designe the software of ethernet interface, and configurated the VPN serve in the system control center.At the end of the paper, we summarize the study and propose further improved methods and follow up researchers.