Table Of ContentAsterisk 1.4
The Professional's Guide
Implementing, administering, and consulting on
commercial IP telephony solutions
Colman Carpenter
David Duffett
Nik Middleton
Ian Plain
BIRMINGHAM - MUMBAI
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
Asterisk 1.4
The Professional's Guide
Copyright © 2009 Packt Publishing
All rights reserved. No part of this book may be reproduced, stored in a retrieval
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critical articles or reviews.
Every effort has been made in the preparation of this book to ensure the accuracy
of the information presented. However, the information contained in this book is
sold without warranty, either express or implied. Neither the authors, nor Packt
Publishing, and its dealers and distributors will be held liable for any damages
caused or alleged to be caused directly or indirectly by this book.
Packt Publishing has endeavored to provide trademark information about all of the
companies and products mentioned in this book by the appropriate use of capitals.
However, Packt Publishing cannot guarantee the accuracy of this information.
First published: August 2009
Production Reference: 1030809
Published by Packt Publishing Ltd.
32 Lincoln Road
Olton
Birmingham, B27 6PA, UK.
ISBN 978-1-847194-38-1
www.packtpub.com
Cover Image by Vinayak Chittar ([email protected])
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
Credits
Authors Editorial Team Leader
Colman Carpenter Gagandeep Singh
David Duffett
Project Team Leader
Nik Middleton
Lata Basantani
Ian Plain
Project Coordinator
Reviewers Neelkanth Mehta
Ian Plain
Jared Smith Proofreader
Philippe Lindheimer Laura Booth
Acquisition Editor Production Coordinator
James Lumsden Aparna Bhagat
Technical Editors Cover Work
Gagandeep Singh Aparna Bhagat
Charumathi Sankaran
Indexer
Rekha Nair
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
Foreword
Watching Asterisk move from being a personal coding project to a community of
tens of thousands of programmers and millions of users has been quite the ride
so far! Asterisk is only now hitting its prime, and there are so many more things
that creative people are going to do with the code. The growth of the project over
the years has stunned and pleased me, and it's amazing that well-written and
comprehensive books like this now exist to help more advanced users navigate the
waters of larger and more complex Asterisk installations. Asterisk installations are
now huge, both in numbers of locations and the unimaginably large size of many of
those locations—thousands or tens of thousands of users! Asterisk implementations
are rarely limited by the capability of the software but more often by not knowing
how to utilize it. Books like this play an important role in getting the experience of
those who have already done in the hands of those who want to do.
Hopefully the knowledge here allows you to continue your adventure with Asterisk,
moving from the basics of PBX construction to having the ability to quickly implement
advanced call logic processes and work with the more exotic telephony and VoIP
interfaces. The motto of "There's more than one way to do it!" is almost always true
with Asterisk—this book seems to contain an excellent cross-section of at least one
of those ways to do "it" (whatever "it" happens to be for your application) and you'll
quickly think of many other ways once you've mastered the methods shown.
The authors here have really shown some excellent detailed explanations of how
to use Asterisk, and I hope this provides the incentive for you, the reader, to
experiment in more wide-ranging ways with Asterisk once you've understood the
basics. Most of the Asterisk community has learned with hands-on experimentation,
and it's great to see more encouragement of this type of learning as is contained in
these pages. Kudos to the authors, especially David Duffett, who has been involved
with Asterisk for so long and has taught so many people their first dialplan routines
(and hopefully has left them uninjured from his famous habit of throwing candy at
people who give correct answers in class or in his talks).
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
Soon you'll be doing least-cost-routing, integrating your instant messenger system
with your mobile phone calls, controlling robots with voice commands via your
phone, or dreaming up a new company based on some voice-based service that
nobody has tapped into yet. And the best thing about Asterisk is that it remains
open source—if you come up with a feature or enhancement that you think must be
in Asterisk, then the good news is that it can be! Become a member of the Asterisk
community, and your contributed code could be included. We all anxiously await
your book, your product, or just your involvement with the Asterisk community.
Mark Spencer
Chairman and CTO of Digium
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
About the Authors
Colman Carpenter is the MD of Voicespan, a Kent-based company that offers
Asterisk-based systems to the SME market across the UK. He is an IT professional
of over 20 years standing, with experience in diverse areas such as IBM mid-range
software development, Lotus Notes and Domino consultancy, Data Management,
E-marketing consultancy, IT Management, Project Management, Wordpress Website
Design, and lately, Asterisk consultancy. He is a qualified PRINCE2 practitioner.
Voicespan (http://www.voicespan.co.uk) offers Asterisk-based systems as the
cornerstone of a holistic VoIP-telephony service for SMEs. They offer companies a
one-stop shop for implementing a VoIP-capable system, encompassing Asterisk-based
systems, endpoints, trunks, telephony interfaces and network equipment, and the
consultancy necessary to bring it all together into a coherent whole. This is his
first book.
I would like to thank my wife, Hazel, and daughters, Caiti and Fay,
for their support during the writing of this book. At times it seemed
like you believed more than I in my ability to do so!
David Duffett delivers Asterisk training and consultancy around the world
through his own company (TeleSpeak Limited, www.telespeak.co.uk), in
addition to designing and delivering training for a number of companies,
including Digium, Inc.
A keen Asterisk enthusiast, David also enjoys podcasting, radio presenting, and
teaching public-speaking skills. He is a Chartered Engineer with experience in
fields including Air Traffic Control communications, Wireless Local Loop, Mobile
Networks, VoIP, and Asterisk. David has been in the telecoms sector for nearly
20 years and has had a number of computer telephony, VoIP, and Asterisk articles
published through various industry publications and web sites.
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
Nik Middleton has been in wide-area communications since the mid-eighties.
He spent most of the nineties working in the US, where he developed a shareware
Microsoft mail to SMTP/POP3 connector that sold some 287,000 copies. He spent six
years working for DuPont in VA, developing remote monitoring systems for their
global Lycra business. In late 2000, he returned to the UK where he held various
senior positions in British Telecom, LogicaCMG, and Computer Science Corp.
In 2005, tired of working in London, he set up his own company (Noble Solutions)
providing VoIP solutions in rural Devon, where he now lives with his wife Georgina
and three children, Mathew, Vicky, and Isabel. A keen amateur pilot, his favorite
place when not in the office is flying over the beautiful Devon countryside.
Ian Plain has worked in the telecoms industry since 1981 and has designed some of
the largest PBX networks in the UK. Since the late 1990s, he has been involved with
VoIP initially for links between systems, and with IP PBX systems since 1999. Since
2003, he has been running a telecoms consultancy based near Bath in the UK, working
primarily on high-availability Asterisk-based solutions for corporate customers.
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
About the Reviewers
Ian Plain: Please see the entry in About the Authors.
Jared Smith is the Training Manager for Digium, Inc. As a long time Asterisk user,
contributor, and evangelist, he has spent the last several years helping the Asterisk
community. Jared is a dynamic and knowledgeable instructor with several years of
experience in leading various Asterisk training classes.
He is also co-author of Asterisk: The Future of Telephony, O'Reilly Media and regularly
writes other Asterisk documentation as well.
Jared holds a Bachelors of Science degree in Computer Engineering from the Utah
State University and currently lives in Virginia with his wife and two children.
Philippe Lindheimer is the project leader and primary developer of FreePBX and
serves as the Open Source Community Director at Bandwidth.com, the corporate
sponsor of the FreePBX project (the most widely deployed Asterisk-based PBX/
GUI open-source application in the world). He cofounded and runs the Open
Telephony Training Seminar providing FreePBX/Asterisk technical and marketing
training to resellers and end users. Originally with Hewlett Packard, he has been
in the engineering industry for over two decades, working on a range of technical
consulting roles with many Fortune 500 Companies.
He has a BS (Hons) in EE/CS from the University of Colorado, Boulder. He now
lives in the Seattle, WA area.
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
This material is copyright and is licensed for the sole use by Anna Indahl on 12th August 2009
PSC 94 Box 361, , APO, , 09824
