Layer 2 Tunneling Protocol (L2TP) has emerged as a key technology in the construction of Virtual Private Networks. L2TP provides remote access capabilities to organizations using public networks for internal, private activities. It allows a corporation to retain the advantages of a private network--privacy of communication, access control, and company addressing--while reducing the need to invest heavily in networking infrastructure. L2TP: Implementation and Operation is an essential resource for anyone who works with L2TP and Virtual Private Networks. Written for developers and network managers, the book provides an overview of the protocol, a detailed explanation of L2TP architecture, a step-by-step guide to its implementation, and information on L2TP security and management. You will find useful background on the OSI model, the underlying PPP technology, how L2TP tunnels PPP, and the L2TP LAC and LNS Layer 2 roles. In addition, the book contains detailed information on such topics as: *L2TP deployment models *L2TP tunnel structure, terminology, and function *Protocol state machines *Tunnel authentication and initiation *Header and control message format, including AVP *Control channel dynamics *Session setup *Proxy authentication *Data handling, including Multilink PPP *L2TP security *SNMP management of L2TP networks *Comparisons with L2F, PPTP, and other VPN technologies Throughout, the book highlights implementation tips, drawn from the author's extensive practical experience, that will help you avoid potential problems and maximize the benefits of L2TP. 0201604485B04062001