TrixBox is a telephone system based on the popular open source Asterisk PBX (Private Branch eXchange) Software. TrixBox allows an individual or organization to setup a telephone system with traditional telephone networks as well as Internet based telephony or VoIP (Voice over Internet Protocol). SugarCRM is already integrated with Asterisk, hence it has been bundled with Trixbox too to increase flexibility. This book guides the reader in the setup of this system and how to manage the telephone system. The book begins by introducing telephony concepts before detailing how to plan a telephone system and moving on to the installation, configuration, and management of a feature packed PBX. This book provides examples of a well laid out telephone system with accompanying spreadsheets to aid the reader in building stable telephony infrastructure.