Asterisk : The Future of Telephony

by Van Meggelen, Jim

• ISBN13: 9780596009625
• ISBN10: 0596009623
• Format: Paperback
• Copyright: 2005-08-01
• Publisher: Oreilly & Associates Inc

Summary

For those new to Asterisk, this book provides a complete roadmap for installation, configuration, and integration with existing phone systems. Primarily aimed at experienced Linux power users or administrators, Asterisk : The Future of Telephony assumes little or no Asterisk experience, and no more than rudimentary telecommunicaitons knowledge. It walks a reader, step-by- step, through a basic dialplan and provides working knowledge that culminates in a simple, but complete system.

Author Biography

1. Jim Van Meggelen

   Jim Van Meggelen is President and CTO of Core Telecom Innovations, a Canadian-based provider of open-source telephony solutions. He has over fifteen years of enterprise telecom experience, for such companies as Nortel, Williams and Telus, and has has extensive knowledge of both legacy and VoIP equipment from manufacturers such as Nortel, Cisco and Avaya. Jim was the architect of two of the world's largest managed enterprise voice networks; each solution serving roughly twenty-thousand users in more than one-thousand communities across Canada, providing telecommunications in five different languages, through six time zones, administered completely from a central location. These networks pioneered the use of extensive automation and database control in a branch voice network - functionalities not generally available in proprietary telecommunications systems. Jim has now moved on from the world of proprietary telecom, and is commited to open-source telephony. Jim is one of the principal contributors to the Asterisk Documentation Project, and is co-authoring the upcoming O'Reilly book, Asterisk: The Future of Telephony. He enjoys teaching, public speaking, improvisational acting, and writing.

2. Jared Smith

   Jared Smith is a long time member of the Asterisk community, and a co-founder of the Asterisk Documentation Project. Jared has over a decade of systems administration and programming experience, along with several years of professional telephony and voice-over-IP experience. As the architect of one of the world's largest Asterisk installations, he has a wealth of hands-on Asterisk knowledge. Jim Van Meggelen is President and CTO of Core Telecom Innovations, a Canadian-based provider of open-source telephony solutions. He has over fifteen years of enterprise telecom experience, for such companies as Nortel, Williams and Telus, and has extensive knowledge of both legacy and VoIP equipment from manufacturers such as Nortel, Cisco and Avaya. Jim is one of the principal contributors to the Asterisk Documentation Project. 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.

3. Leif Madsen

   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.

Table of Contents

Foreword	ix
Preface	xiii
A Telephony Revolution	1	(8)
VoIP: Bridging the Gap Between Traditional Telephony and Network Telephony	2	(1)
Massive Change Requires Flexible Technology	3	(2)
Asterisk: The Hacker's PBX	5	(1)
Asterisk: The Professional's PBX	5	(1)
The Asterisk Community	5	(2)
The Business Case	7	(1)
This Book	8	(1)
Preparing a System for Asterisk	9	(22)
Server Hardware Selection	10	(8)
Environment	18	(4)
Telephony Hardware	22	(3)
Types of Phone	25	(5)
Linux Considerations	30	(1)
Conclusion	30	(1)
Installing Asterisk	31	(27)
What Packages Do I Need?	31	(1)
Obtaining the Source Code	32	(3)
Compiling Zaptel	35	(6)
Compiling libpri	41	(1)
Compiling Asterisk	41	(5)
Installing Additional Prompts	46	(1)
Updating Your Source Code	46	(1)
Common Compiling Issues	47	(3)
Loading Zaptel Modules	50	(2)
Loading libpri	52	(1)
Loading Asterisk	52	(2)
Directories Used by Asterisk	54	(3)
Conclusion	57	(1)
Initial Configuration of Asterisk	58	(19)
What Do I Really Need?	58	(1)
Working with Interface Configuration Files	59	(1)
FXO and FXS Channels	60	(1)
Configuring an FXO Channel	61	(4)
Configuring an FXS Channel	65	(2)
Configuring SIP	67	(5)
Configuring Inbound IAX Connections	72	(2)
Configuring Outbound IAX Connections	74	(1)
Debugging	75	(1)
Conclusion	76	(1)
Dialplan Basics	77	(22)
Dialplan Syntax	77	(4)
A Simple Dialplan	81	(3)
Adding Logic to the Dialplan	84	(14)
Conclusion	98	(1)
More Dialplan Concepts	99	(20)
Expressions and Variable Manipulation	99	(3)
Dialplan Functions	102	(1)
Conditional Branching	103	(3)
Voicemail	106	(4)
Macros	110	(2)
Using the Asterisk Database (AstDB)	112	(3)
Handy Asterisk Features	115	(3)
Conclusion	118	(1)
Understanding Telephony	119	(18)
Analog Telephony	119	(3)
Digital Telephony	122	(8)
The Digital Circuit-Switched Telephone Network	130	(5)
Packet-Switched Networks	135	(1)
Conclusion	136	(1)
Protocols for VoIP	137	(19)
The Need for VoIP Protocols	138	(1)
VoIP Protocols	139	(5)
Codecs	144	(4)
Quality of Service	148	(3)
Echo	151	(1)
Asterisk and VoIP	152	(3)
Conclusion	155	(1)
The Asterisk Gateway Interface (AGI)	156	(19)
Fundamentals of AGI Communication	156	(3)
Writing AGI Scripts in Perl	159	(4)
Creating AGI Scripts in PHP	163	(6)
Writing AGI Scripts in Python	169	(3)
Debugging in AGI	172	(2)
Conclusion	174	(1)
Asterisk for the Uber-Geek	175	(15)
Festival	175	(3)
Call Detail Recording	178	(1)
Customizing System Prompts	179	(1)
Manager	180	(2)
Call Files	182	(2)
DUNDi	184	(5)
Conclusion	189	(1)
Asterisk: The Future of Telephony	190	(19)
The Problems with Traditional Telephony	190	(3)
Paradigm Shift	193	(1)
The Promise of Open Source Telephony	193	(7)
The Future of Asterisk	200	(9)
VoIP Channels	209	(20)
Application Reference	229	(63)
AGI Reference	292	(9)
Configuration Files	301	(36)
Asterisk Command-Line Interface Reference	337	(22)
Index	359