In typical O’Reilly fashion, this is a very readable guide for installing and administering Asterisk, the open-source solution for Voice over IP that runs on Linux. Step-by-step instructions are given, which is very necessary in a very new product that is short on documentation. There are even a few chapters that discuss basic telephony technology and others that discuss where Voice over IP has been and where it may be going in the context of open source solutions such as Asterisk, so this is not just a dry boring instruction manual. I notice that Amazon does not have the table of contents available, so I show and describe that here:

Chapter 1 “A Telephony Revolution” is just an introduction to Voice over IP and how it differs from computer integrated telephony solutions of just a few years ago.

Chapter 2 “Preparing a System for Asterisk” is about selecting server hardware, telephony hardware, different types of phones, and Linux considerations.

Chapter 3 “Installing Asterisk” tells you what packages you will need, how to obtain the source code, and how to compile, install, and update your source code.

Chapter 4 “Initial Configuration of Asterisk” is about working with interface configuration files, FXO and FXS channels and their configuration, configuring SIP, and configuring inbound and outbound connections. Debugging issues are also raised.

Chapters 5 and 6 are about dialplans. This ranges from dialplan basics and syntax to adding logic to a dialplan. Also expressions and variable manipulation as well as dialplan functions are discussed. Finally, the Asterisk database is discussed. These two chapters are what I consider to be the meatiest part of the book.

Chapter 7 “Understanding Telephony” discusses general telephony technology. Both analog and digital systems are discussed. The digital circuit-switched telephone network and packet-switched networks are explained.

Similarly, chapter 8, “Protocols for VoIP” discusses the need for VoIP protocols, the protocols themselves, codecs, the concept of quality of service and echo, and finally how Asterisk fits into VoIP.

Chapter 9 is about the Asterisk Gateway Interface and how to write scripts for it in a variety of common languages. This is very interesting material for advanced users who enjoy programming.

Chapter 10 is about advanced concepts and includes details on Festival, call detail recording, customized system prompts, and call files.

Chapter 11, the final chapter, is about the future of telephony and how Asterisk might fit into that future.

There are several useful appendices in the back of the book on VoIP channels, an application reference, an AGI reference, a section on configuration files, and finally an Asterisk command-line interface reference.

Rating: 5 / 5

The few reviewers who preceded me were a little star-happy with this book, I believe, despite pointing out some serious shortcomings.

I could probably say that this is the best book currently available on Asterisk, but then again, this is almost the only book available on Asterisk…

The THREE authors produced a mere 208 pages; the remainder is in the form of appendices. And when you factor in the space consumed by scripting examples, you’ll realize how you finished the book so quickly.

Some of the chapters do warrant merit. A chapter on hardware requirements for Asterisk was helpful, and those pertaining to the dialplan and AGI scripting were supported with some useful sample code. But instead of delving into important areas like SIP and interfacing with service providers, the authors chose to write too much about Free World Dialup, for example. For those seriously considering Asterisk as a business communications platform, this hobbyist approach to the subject is not amusing.

(One final complaint: O’Reilly should be ashamed for allowing so many typographical errors to make it into print.)

Asterisk needs a thoroughly written manual for the telecom professional: this is not that book. However, if you are new to Asterisk and have never done any programming, this book is still recommended, if for no other reason than it’s the only other (current) option apart from online material.
Rating: 2 / 5

I bought this book because I thought that having a small PBX-type system for my home/office would allow me to route faxes to my fax machine, provide voicemail to replace the limited answering machine, and auto attendant menus to route calls to 1 of 3 extensions that I would be able to configure. I saw a solution that would divide business and personal calls and also filter and perhaps stop once and for all those evil telemarketing calls.

In reading the book and doing a little research I learned that my goals were modest indeed for what the system is capable of!

While the idea is to provide a business-level PBX with inexpensive hardware, the same thing can be used as a killer phone appliance for the home or small office.

Even though I am about a quarter of the way into it, I can tell you that this book is one of the best written technical guides I have ever read. It’s easy to read and chock-full of practical information that considers several types of users in it’s presentation.

Don’t expect to be a beginner and have an easy time of understanding how to install and configure an Asterisk PBX. Even for those with extensive computer experience there are a number of new terms, concepts, and technologies to learn. But if you have the interest and time to spend, you will be rewarded in taking full control of your phone system and be able to expand that control to home automation and other functions limited only by your imagination and programming skill.

I think Asterisk is going to turn into a household name at some point and skills learned today could turn into a career tomorrow.
Rating: 5 / 5