This book will give you a firm understanding of Asterisk Gateway Interface (AGI) AGI development practices and proper development. This book builds from the simplest form of application Asterisk, dialplan-based applications, gradually build a full understanding of AGI scripting. This book takes a pragmatic approach with clear examples and complete, and project development services - allowing you to understand the cycle of development projects Asterisk-based services or applications. Unlike most books, which just shows you how to do or what to do, this book tries to show: "why do?" - Thus explaining the logic behind certain Asterisk development paradigm.