FreeSWITCH Cookbook

By Anthony Minessale

This is a problem-solution approach to take your FreeSWITCH skills to the next level, where everything is explained in a practical way. If you are a system administrator, hobbyist, or someone who uses FreeSWITCH on a regular basis, this book is for you. Whether you are a FreeSWITCH expert or just getting started, this book will take your skills to the next level.

• Language: English
• Publisher: Packt Publishing
• Release date: Feb 23, 2012
• ISBN: 9781849515412

Anthony Minessale

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.

Book preview

Table of Contents

FreeSWITCH Cookbook

Credits

About the Authors

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers and more

Why Subscribe?

Free Access for Packt account holders

Preface

What this book covers

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Routing Calls

Introduction

Regular expressions

Important dialplan contexts in the default configuration

The default context

The public context

The features context

Internal calls

Getting ready

How to do it...

How it works...

See also

Incoming DID calls

Getting ready

How to do it...

How it works...

There's more...

See also

Outgoing calls

Getting ready

How to do it...

How it works...

There's more...

See also

Ringing multiple endpoints simultaneously

Getting ready

How to do it...

How it works...

There's more...

See also

Ringing multiple endpoints sequentially (simple failover)

Getting ready

How to do it...

How it works...

There's more...

Handling busy and other failure conditions

Handling no answer conditions

Using individual bridge calls

See also

Advanced multiple endpoint calling with enterprise originate

Getting ready

How to do it...

How it works...

There's more...

Setting variables

Ringback

See also

Time of day routing

Getting ready

How to do it...

How it works...

There's more...

See also

Manipulating To: headers on registered endpoints to reflect DID numbers

Getting ready

How to do it...

How it works...

2. Connecting Telephones and Service Providers

Introduction

Configuring a SIP phone to register with FreeSWITCH

Getting ready

How to do it...

How it works...

There's more...

Caller ID

Customizing context

See also

Connecting audio devices with PortAudio

Getting ready

How to do it...

How it works...

There's more...

See also

Using FreeSWITCH as a softphone

Getting ready

How to do it...

How it works...

There's more...

See also

Configuring a SIP gateway

Getting ready

How to do it...

How it works...

There's more...

Adding prefixes to dial strings

Monitoring gateways

Configuring Google Voice

Getting ready

How to do it...

How it works...

Codec configuration

Getting ready

How to do it...

How it works...

There's more...

Avoiding codec negotiation altogether

3. Processing Call Detail Records

Introduction

Using CSV CDRs

Getting ready

How to do it...

How it works...

There's more...

File names and locations

Other options

CDR CSV templates

See also

Using XML CDRs

Getting ready

How to do it...

How it works...

There's more...

File names and locations

Logging the B leg

See also

Inserting CDRs into a backend database

Getting ready

How to do it...

How it works...

There's more...

See also

Using a web server to handle XML CDRs

Getting ready

How to do it...

How it works...

There's more...

See also

Using the event socket to handle CDRs

Getting ready

How to do it...

How it works...

There's more...

ESL considerations

Receiving XML CDRs

See also

4. External Control

Introduction

Getting familiar with the fs_cli interface

Getting ready

How to do it...

How it works...

There's more...

Important commands for listing information

Useful command line options

Viewing events

See also

Setting up the event socket library

Getting ready

Debian

Red Hat

How to do it...

How it works...

Establishing an inbound event socket connection

Getting ready

How to do it...

How it works...

There's more...

See also

Establishing an outbound event socket connection

Getting ready

How to do it...

How it works...

There's more...

See also

Using fs_ivrd to manage outbound connections

Getting ready

How to do it...

How it works...

See also

Filtering events

Getting ready

How to do it...

How it works...

See also

Launching a call with an inbound event socket connection

Getting ready

How to do it...

How it works...

There's more...

See also

Using the ESL connection object for call control

Getting ready

How to do it...

How it works...

See also

Using the built-in web interface

Getting ready

How to do it...

How it works...

There's more...

Controlling PortAudio

The XML RPC In mod_xml_rpc

See also

5. PBX Functionality

Introduction

Creating users

Getting ready

How to do it...

How it works...

There's more...

Regular expressions with Regexp::Assemble

See also

Accessing voicemail

Getting ready

How to do it...

How it works...

See also

Company directory

How to do it...

How it works...

There's more...

See also

Using phrase macros to build sound prompts

Getting ready

How to do it...

How it works...

There's more...

See also

Creating XML IVR menus

Getting ready

How to do it...

How it works...

There's more...

See also

Music on hold

Getting ready

How to do it...

How it works...

There's more...

Creating conferences

Getting ready

How to do it...

How it works...

There's more...

Caller controls

Conference moderator and PIN

Sending faxes

Getting ready

How to do it...

How it works...

There's more...

Detecting a fax machine and responding

Diagnosing fax issues

Helpful software

See also

Receiving faxes

Getting ready

How to do it...

How it works...

There's more...

Detecting inbound faxes

Processing a received fax

See also

Basic text-to-speech with mod_flite

Getting ready

How to do it...

How it works...

See also

Advanced text-to-speech with mod_tts_commandline

Getting ready

How to do it...

How it works...

There's more...

Modifying the audio stream

Other TTS engines

Configuration file examples

See also

Listening to live calls with telecast

Getting ready

How to do it...

How it works...

See also

Recording calls

Getting ready

How to do it...

How it works...

There's more...

See also

Index

FreeSWITCH Cookbook

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FreeSWITCH Cookbook

Copyright © 2012 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 published: February 2012

Production Reference: 1160212

Published by Packt Publishing Ltd.

Livery Place

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Birmingham B3 2PB, UK.

ISBN 978-1-84951-540-5

www.packtpub.com

Cover Image by Asher Wishkerman (<[e-mail]>)

Credits

Authors

Anthony Minessale

Michael S Collins

Darren Schreiber

Raymond Chandler

Reviewers

Jonathan Augenstine

Eric Z. Beard

Hugh Irvine

Acquisition Editor

Usha Iyer

Lead Technical Editor

Hithesh Uchil

Technical Editors

Vanjeet D'souza

Prasad Dalvi

Copy Editor

Leonard D'Silva

Project Coordinator

Joel Goveya

Proofreader

Matthew Humphries

Indexer

Monica Ajmera Mehta

Production Coordinator

Arvindkumar Gupta

Cover Work

Arvindkumar Gupta

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 at Barracuda Networks. Anthony created and continues to run the ClueCon Telephony Developers Conference held every August in Chicago.

Anthony has extensive experience in the Internet industry and VoIP. He has 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. This is Anthony's second book; he has also co-authored the FreeSWITCH 1.0.6 book published by Packt Publishing.

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. 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. Michael is an active member of the FreeSWITCH community and has co-authored Packt Publishing's FreeSWITCH 1.0.6. 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. I would also like to thank the many FreeSWITCH experts around the world who are so willing to answer technical questions: Michael Jerris, Moises Silva, Raymond Chandler, Mathieu René, Ken Rice, and many more. I would especially like to thank Brian K. West for patiently educating me in the ways of VoIP.

Finally, I give my continued thanks to Anthony Minessale. In addition to authoring an amazing piece of software he has graciously let me work closely with the very talented core FreeSWITCH development team.

Darren Schreiber is the CEO and Co-Founder of 2600hz. 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. Darren's 15 years of voice and IT experience include developing multiple enterprise SaaS infrastructures for hosting and remotely managing IT, voice, and e-commerce services. Darren 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. Darren graduated from Rensselaer Polytechnic Institute with a degree in Computer Science and Business Management.

Darren is also a co-author on the original FreeSWITCH Telephony Book.

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 morale support for our work. Specifically my parents who demand a check-in on how things are going at least once a week. 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, Raymond still had not found his perfect solution.

In 2006, Raymond was introduced to FreeSWITCH. Since then, he's been using FreeSWITCH and regularly contributing to the community. Raymond is the author of mod_lcr and several utility PHP/perl scripts. Raymond now works with Anthony Minessale as a CudaTel Software Engineer at Barracuda Networks (@CudaTel and @BarracudaLabs).

In the spring of 2011, Raymond 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, and our children