Book excerpt: Asterisk has a wealth of features to help you customize your PBX to fill very specific business needs. This short cookbook offers recipes for tackling dialplan fundamentals, making and controlling calls, and monitoring channels in your PBX environment. Each recipe includes a simple code solution you can put to work immediately, along with a detailed discussion that offers insight into why and how the recipe works. This book focuses on Asterisk 1.8, although many of the conventions and information presented are version-agnostic. These recipes include solutions to help you: Authenticate callers before moving on in your dialplan Redirect calls received by your auto-attendant Create an automatic call-back service Initiate hot-desking to login to and accept calls at any office device Monitor and interrupt live calls to train new employees at a call center Record calls from your Asterisk dialplan