So where to begin? Well, when it comes to Asterisk, there is far more to talk about than we can fit into one book. For now, we’re not going to take you down all the roads that the über-geeks follow—we’re just going to give you the basics.
In Chapter 2, Preparing a System for Asterisk, we cover some of the engineering considerations you should keep in mind when designing a telecommunications system. You can skip much of this material if you want to get right to installing, but these are important concepts to understand, should you ever plan on putting an Asterisk system into production.
Chapter 3, Installing Asterisk covers obtaining, compiling, and installing Asterisk, and Chapter 4, Initial Configuration of Asterisk deals with the initial configuration of Asterisk. Here we cover the important configuration files that must exist to define the channels and features available to your system. This will prepare you for Chapter 5, Dialplan Basics, where we introduce the heart of Asterisk—the dialplan. Chapter 6, More Dialplan Concepts will introduce some more advanced dialplan concepts.
We will take a break from Asterisk in Chapter 7, Understanding Telephony and discuss some of the more important technologies in use in the PSTN. Naturally, following the discussion of legacy telephony, Chapter 8, Protocols for VoIP discusses Voice over IP.
Chapter 9, The Asterisk Gateway Interface (AGI) introduces one of the more amazing components, the Asterisk Gateway Interface (AGI). Using Perl, PHP, and Python, we demonstrate how external programs can be used to add nearly limitless functionality to your PBX. In Chapter 14, Potpourri, we briefly cover what is, in fact, a rich and varied cornucopia of incredible features and functions, all of which are part of the Asterisk phenomenon. To conclude, Chapter 15, Asterisk: The Future of Telephony looks forward, predicting a future where open source telephony completely transforms an industry desperately in need of a revolution. You’ll also find a wealth of reference information in the book’s five appendixes.
This book can only lay down the basics, but from this foundation you will be able to come to an understanding of the concept of Asterisk—and from that, who knows what you will build?