Research On Virtual Private Network And Implement Of The System

This dissertation addresses the techniques of Virtual Private Network, and proposed a way to implement a VPN system based on IPSec on Windows platform.VPN(Virtual Private Network) is the result of developing of Internet technology and requirement of commerce, which is to build a security virtual private network beyond an insecurity public network. VPN is a way to provide service, and doesn't prescribe how to implement it. The normal way is to tunneled original data from private network with tunnel protocol, to transfer the tunneled data on public network(such as Internet),provide confidentiality to ensure the security of the communication by the encryption techniques and in-depth service, such as QoS, identity authentication, origin authentication, access control.There are a lot of protocols to build VPN system, which locate in several lays of the TCP/IP stacks. Among those protocols, IPSec is said to be the best one and has become the primary way to implement VPN system. At the same time, MPLS has been developed and comes to be another primary protocol to implement VPN by telecomm service provider.In this dissertation, we introduce the theory of Virtual Private Network, analyze several leading protocols, and choose IPSec as a model. Aim at the national situation, we research on key techniques to implement VPN system based on IPSec on Windows. With the research on IPSec protocols, we propose a scheme and implemented the system based on the research.The test shows the system runs steady on Windows 98,ME,2000, and get great efficiency. As the system is implement by ourselves, we can add encryption and authentication arithmetic to maintain the requirement of the specifically environment.