Asterisk: The Future of Telephony (Paperback)

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Product Description

It may be a while before Internet telephony with VoIP (Voice over Internet Protocol) reaches critical mass, but there's already tremendous movement in that direction. A lot of organizations are not only attracted to VoIP's promise of cost savings, but its ability to move data, images, and voice traffic over the same connection. Think of it: a single Internet phone call can take information sharing to a whole new level.

That's why many IT administrators and developers are actively looking to set up VoIP-based private telephone switching systems within the enterprise. The efficiency that network users can reach with it is almost mind-boggling. And cheap, if the system is built with open source software like Asterisk. There are commercial VoIP options out there, but many are expensive systems running old, complicated code on obsolete hardware. Asterisk runs on Linux and can interoperate with almost all standards-based telephony equipment. And you can program it to your liking.

Asterisk's flexibility comes at a price, however: it's not a simple system to learn, and the documentation is lacking. Asterisk: The Future of Telephony solves that problem by offering a complete roadmap for installing, configuring, and integrating Asterisk with existing phone systems. Our guide walks you through a basic dial plan step by step, and gives you enough working knowledge to set up a simple but complete system.

What you end up with is largely up to you. Asterisk embraces the concept of standards-compliance, but also gives you freedom to choose how to implement your system. Asterisk: The Future of Telephony outlines all the options, and shows you how to set up voicemail services, call conferencing, interactive voice response, call waiting, caller ID, and more. You'll also learn how Asterisk merges voice and data traffic seamlessly across disparate networks. And you won't need additional hardware. For interconnection with digital and analog telephone equipment, Asterisk supports a number of hardware devices.

Ready for the future of telephony? We'll help you hook it up.

About the Author

Leif Madsen first took an interest in Asterisk while attempting to find a voice conferencing solution for him and his friends. After someone suggested trying Asterisk, the obsession began. Wanting to contribute and be involved with the community, and noticing the lack of Asterisk documentation, he co-founded the Asterisk Documentation Project.

Product Details

• Paperback: 408 pages
• Publisher: O'Reilly Media; illustrated edition edition (September 16, 2005)
• Language: English
• ISBN-10: 0596009623
• ISBN-13: 978-0596009625
• Product Dimensions: 8.9 x 7 x 1 inches
• Shipping Weight: 1.5 pounds
• Average Customer Review: 4.1 out of 5 stars  See all reviews (30 customer reviews)
• Amazon.com Sales Rank: #142,252 in Books (See Bestsellers in Books)

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Customer Reviews

Most Helpful Customer Reviews

20 of 22 people found the following review helpful:

5.0 out of 5 stars Great admin guide and reference, November 15, 2005

By	calvinnme "Texan refugee" (Fredericksburg, Va) - See all my reviews (TOP 10 REVIEWER)

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.

12 of 13 people found the following review helpful:

3.0 out of 5 stars Bleah, January 17, 2007

By	orangekay (San Francisco, CA United States) - See all my reviews

This book really isn't all that great and leaves many a stone unturned for novice and professional alike, but I'll give it three stars anyway just because you can legally download an electronic copy for free right from the "Support" section of the main Asterisk website.

If you want a book that's going to explain how to configure VoIP hardware that isn't sold by Digium, try "Switching to VoIP" and just stick to the online docs and sample config comments for Asterisk.

13 of 15 people found the following review helpful:

2.0 out of 5 stars Asterisk still lacks professional documentation, October 21, 2005

By	Jason A. Copson - See all my reviews (REAL NAME)

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.