FreeSWITCH 1.2 Second Edition Build robust, high-performance telephony systems using FreeSWITCH Anthony Minessale Michael S Collins Darren Schreiber Raymond Chandler BIRMINGHAM - MUMBAI FreeSWITCH 1.2 Second Edition Copyright © 2013 Packt Publishing All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in 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 edition: July 2010 Second edition: May 2013 Production Reference: 1170513 Published by Packt Publishing Ltd. Livery Place 35 Livery Street Birmingham B3 2PB, UK. ISBN 978-1-78216-100-4 www.packtpub.com Cover Image by Suresh Mogre ([email protected]) Credits Authors Project Coordinator Anthony Minessale Arshad Sopariwala Michael S Collins Darren Schreiber Proofreader Paul Hindle Raymond Chandler Indexer Reviewers Monica Ajmera Mehta Norm Brandinger Kristian Kielhofner Graphics Jeff Leung Abhinash Sahu Brian Wiese Production Coordinator Acquisition Editor Pooja Chipulunkar Usha Iyer Cover Work Lead Technical Editor Pooja Chipulunkar Ankita Shashi Technical Editors Chirag Jani Soumya Kanti Ankita Meshram Dheera Meril Paul Zafeer Rais About the Authors Anthony Minessale has been working with computers for nearly 30 years. He is the primary author of FreeSWITCH and Director of Engineering for CudaTEL at Barracuda Networks. He created and continues to run the ClueCon Telephony Developers Conference, held every August in Chicago. He has extensive experience in the Internet industry and VoIP. Before creating FreeSWITCH, he contributed heavily to the Asterisk open source project, producing many features that are still in use today. At Barracuda Networks, Anthony oversees the production and development of the CudaTEL PBX appliance that uses FreeSWITCH as its core telephony engine. I would like to thank my awesome family: my wife, Jill, son, Eric, and daughter, Abbi, for putting up with the long hours and supporting me on my cause to revolutionize the telephony industry. Thanks to my dogs, Chewie and Gypsy, for staying up with me at 2 a.m. on long nights. I would also like to thank the open source community at large, especially those involved in the FreeSWITCH project, and I hope to see you all every summer at ClueCon! Michael S Collins is a telephony and open source software enthusiast. He is a PBX veteran, having worked as a PBX technician for five years and as the head of IT for a call center for more than nine years. He is an active member of the FreeSWITCH community and has co-authored FreeSWITCH Cookbook, Packt Publishing. He resides in Central California with his wife and two children and currently works for Barracuda Networks, Inc. I would like to thank first and foremost my wife, Lisa, my daughter, Katherine, and my son, Sean, who keep me going each day. Without them I could not contribute to open source projects like FreeSWITCH, much less co-author a book. I would also like to thank the many FreeSWITCH experts around the world who are so willing to answer technical questions: Anthony Minessale, Michael Jerris, Moises Silva, Raymond Chandler, Ken Rice, Travis Cross, and many more. I would especially like to thank Brian K. West for patiently educating me in the ways of VoIP. I am also grateful to the many people who devote themselves to answering questions on the FreeSWITCH mailing list and IRC channel: Steven Ayre, Avi Marcus, Steve Underwood, and all the rest. The FreeSWITCH worldwide community is a great example of what an open source community should be. Well done! Darren Schreiber is the CEO and Co-founder of 2600 Hz. He began working heavily in open source voice with the FreeSWITCH project, where he engaged with Brian, Mike, and Anthony. His projects have since evolved into two enterprise VoIP platforms that allow a multitude of development of voice, SMS, and video applications to be delivered to customers. He has 15 years of voice and IT experience including developing multiple enterprise SaaS infrastructures for hosting and remotely managing IT, voice, and e-commerce services. He is a guest lecturer at major universities on VoIP technology and leads paid international VoIP trainings. As a serious telephony enthusiast since a young age, he has worked extensively with VoIP technologies. He graduated from Rensselaer Polytechnic Institute with a degree in Computer Science and Business Management. He is also a co-author of FreeSWITCH Cookbook, Packt Publishing. I'd like to thank, first and foremost, the FreeSWITCH team. Without them, I wouldn't have been challenged with some of the most intriguing technology and people I've ever worked with. It has been a gift working with them. I'd also like to thank my family and friends who have put up with my crazy work schedule and constant tardiness, and have helped provide funds and moral support for our work. Thanks for everything. Finally, I'd like to thank the open source community. Their tireless patience and countless selfless contributions are a constant reminder that the world is not an evil place, and that people are generally out for the greater good of society. Raymond Chandler(@intralanman) has been working with, and contributing to, open source projects for over a decade. Raymond's VoIP experience started with a small CLEC/ITSP using SER for call routing, and Asterisk for voicemail and advanced services. After encountering limits in Asterisk and looking for features not easily found in SER, he moved to using OpenSER and CallWeaver (then known as OpenPBX.org). While that combination was better, he still had not found his perfect solution. In 2006, he was introduced to FreeSWITCH. Since then, he's been using FreeSWITCH and regularly contributing to the community. He is the author of mod_lcr and several utility PHP/Perl scripts. He now works with Anthony Minessale as a CudaTel Software Engineer at Barracuda Networks (@CudaTel and @Barracuda). In the spring of 2011, he was among the founding members of the Open Source Telephony Advancement Group (@OSTAG), whose mission is to advance open source telephony to new heights by funding open source projects through funds received by generous contributions and grants from those who share the OSTAG vision. I'd like to thank my loving wife, Samantha, our daughters Makenzie, Trinity, Alecsys, and Kristian, and our sons Kaiden and Casper for their support while they get less time with me than any of us would like. I'd also like to thank the countless volunteers who step up to help out in the FreeSWITCH and other open source project communities. It would be impossible to keep any project running without them. About the Reviewers Norm Brandinger has worked in the computer industry focusing in the areas of systems programming and communications for many years. He graduated with an Engineering Degree in Computer Science from the University of Florida just before the industry began experiencing the exponential growth that continues today. He has worked on the communication challenges that Fortune 100, mid-sized, and small companies all face as an owner, employee, and consultant. Today he balances his high-tech career with a love of the outdoors. Hiking in the woods, climbing mountains, and biking are just some of the ways he finds some balance. He would not be where he is today without the support, love, guidance, and good genes from his parents. His mom is a retired Special Education professor from Trenton State College. Most recently, his dad was the Executive Director of the New Jersey Commission on Science and Technology. His brother Paul also inherited some good genes as he now works for NASA's Goddard Space Flight Center. I would like to acknowledge and thank my partner, Donna. She works full time as a nurse, yet manages to find the time to take care of much of the home and social responsibilities. Her tireless efforts are the reason I have had the time to work on this project. Kristian Kielhofner is the Co-founder and Chief Technology Officer of Star2Star Communications, The World's Most Reliable Business Grade Communications Solution. He is the inventor and architect of Star2Star's patent-pending StarPath and Constellation technologies. Prior to joining Star2Star, he was most well known as the creator and maintainer of AstLinux, the first Linux distribution to target embedded devices for open source telephony applications. Jeff Leung is a Small Business Networking Consultant and a Telecommunications Technician. He has seven years of experience in various networking protocols and network architectures including Microsoft Active Directory Networks, Legacy Nortel PBX systems, and FreeSWITCH IP-PBX systems. He started learning networking protocols at the age of 14 when he stumbled across a book about Active Directory networks at his local library, and the experiences and self-teaching of networking protocols started to snowball from there, eventually turning a hobby into a career that he is very passionate about. I extend my thanks to the Richmond Public Library located in Richmond, British Columbia for jumpstarting my career with the selection of printed material, and my family for the support they have given me during my tenure at British Columbia Institute of Technology for further training in the Telecommunications and Networking career.