Asterisk: The Definitive Guide (repost)

Design a complete VoIP or analog PBX with Asterisk, even if you have no previous Asterisk experience and only basic telecommunications knowledge. This bestselling guide makes it easy, with a detailed roadmap to installing, configuring, and integrating this open source software into your existing phone system.

Ideal for Linux administrators, developers, and power users, this book shows you how to write a basic dialplan step by step, and quickly brings you up to speed on the latest Asterisk features in version 1.8.
Integrate Asterisk with analog, VoIP, and digital telephony systems
Build a simple interactive dialplan, and dive into advanced concepts
Use Asterisk’s voicemail options—including a standalone voicemail server
Build a menuing system and add applications that act on caller input
Incorporate a relational database with MySQL and Postgre SQL
Connect to external services such as LDAP, calendars, XMPP, and Skype
Use Automatic Call Distribution to build a call queuing system
Learn how to use Asterisk’s security, call routing, and faxing features