Research On Layer 2 Tunneling Protocols And Implementation Of L2TPv3 Data Layer

Virtual Private Network (VPN) techniques are becoming more and more important in organization of Intranets for geographically dispersed enterprises or communities. The layer 2 tunneling technique is one of the VPN techniques, which is dedicated to ferry the layer 2 protocols through public data networks.The background of this dissertation is Virtual Private Networks (VPN), with an emphasis on Level 2 tunneling techniques. This dissertation presented a theoretical work as well as an experimental implementation of the L2TP carried out at the Sichuan Network Communication Key Laboratory. This project was spurred by idea of extending the application of the tunneling technique to a broad area as a result of a preliminary study on tunneling techniques, especially on L2F, PPTP and L2TP (commonly referred to as L2TPv2). Such idea is intended to apply tunneling techniques to protocols not only to level 2 protocols as defined in newest version in IETF draft standard (L2TPv3) but also to protocols in other layers.The work presented in this dissertation covers:1. A comprehensive study of layer 2 tunneling techniques: the incentive behind and the essence of tunneling techniques, and changes in different versions and a forward view in future application.2. A comparatively complete implementation of L2TPv3 base on the idea of the extension to tunneling techniques, which the author has chiefly contributed to the design and realization of the data layer module in the kernal and relevant test.