Revised for the upcoming 1.8 release of the Asterisk open source PBX, this bestselling guide provides a complete roadmap for installing, configuring, and integrating this powerful software with existing phone systems. Asterisk: The Definitive Guide has everything you need to know to design a complete VoIP or analog system with little or no Asterisk experience, and no more than rudimentary telecommunications knowledge.Written for experienced Linux power users and administrators, this book shows you how to write a basic dialplan step-by-step, and quickly gets you up to speed on several features new to Asterisk, including: Skype for Asterisk Fax capabilities (T.38) Clustering with Open AIS Jabber integration and XMPP Heartbeat cluster infrastructure (LinuxHA, failover) ISN and ENUM -- methods of circumventing the PSTN by dialing SIP URIs with numbers Security profile for Real-time Transport Protocol (RTP) Internet Protocol version 6 (IPv6)