Study Of Virtual Private Network Based On IPSec

Virtual Private Networks (VPNs) are one of the most promising methods available for leveraging the power of public networks for private networking applications. VPNs provide secure and stable tunnels through shared IP-based networks for remote access.extranet. and Intranet connectivity at a significantly less cost than those associated with private leased lines. VPNs use a technique called tunneling to send encrypted datapackets across the shared network in a private tunnel that simulates a point-to-pointconnection. The advanced security features of VPN prevent outsiders to penetrate the transmitted data until it reaches its destination.The popularity of multicast has grown considerably with the wide use of Internet. IP multicast is a bandwidth-conserving technology that reduces traffic by simultaneously delivering a single stream of information to thousands of corporate recipients and homes. Applications that take advantage of multicast include videoconferencing, corporate communications, distance learning, and distribution of software, stock quotes, and news. Yet security threats on the Internet have flourished as well. Thus the needs for the secure and efficient multicast is acute.In our paper discussed both VPNs and multicast by two clues. One clue is the research of Virtue Private Network and IPSec. At first, the definition, taxonomy, mplement, management and the key technolodgy are introduced. The Tunelling Techenolodgy , IP Security Protocol is the emphasis of research, including the functions, the modes, domain of interpretation, the series protocols of IPSec. The other clue is the research of multicast. We discussed the application, protocols and the system framework. Then two clues are met, i.e the multicast dataflow is not supported by the VPN, and the security is very difficulty in multicast. So we presenta solutions to the security multicast, which is a system model based on IPSec VPN. The entities, protocols .the roles of system membership and the modules are designed. The machinery , operation functions and relationship of the modules are detailed. Finally, the future application of the system model is explored.