Ip-based Peer-to-peer Distributed Vpn System

Combining the property of distributed systems, raise the concept of distributed VPN and create the system model, which extend the concept of classical VPN. From the aspect of security, it overcomes the classical VPN's disadvantages of failing to protect the internal communication of LANs. The result of analyzing current VPN system indicates that they have disadvantages in aspects of security and efficiency. Based on the model of DVPN, this paper analyses its performance improvement relative to classical VPN. The result indicates that it can enhance the parallelity of the system, reduce the storage requirement from complexity O(2) to O() and make the database grow linearly. Any node can join and quit the system conveniently and transparently. The dial-up user can get equivalent security and efficiency.As well, give a system implementation based on PC and workstation. The test results indicate that the DVPN can not only protect the internal communication of LANs, but also overcome the classical VPN's inherent disadvantages of slow IP packets processing and large storage requirements. The loss of efficiency is limited in a controllable scope by considerate system design, which guarantees the design requirement.The analyzing result demonstrates the DVPN has superiority over the classical VPN. Also, it proves that DVPN can improve the security and efficiency of the system.