Asterisk - The Open Source VoIP PBX
Asterisk: The Future of Telephony
Table of Contents
Copyright
Foreword
Preface
Audience
Organization
Software
Conventions Used in This Book
Using Code Examples
Safari® Enabled
How to Contact Us
Acknowledgments
Chapter 1. A Telephony Revolution
Section 1.1. VoIP: Bridging the Gap Between Traditional Telephony and Network Telephony
Section 1.2. Massive Change Requires Flexible Technology
Section 1.3. Asterisk: The Hacker's PBX
Section 1.4. Asterisk: The Professional's PBX
Section 1.5. The Asterisk Community
Section 1.6. The Business Case
Section 1.7. This Book
Chapter 2. Preparing a System for Asterisk
Section 2.1. Server Hardware Selection
Section 2.2. Environment
Section 2.3. Telephony Hardware
Section 2.4. Types of Phone
Section 2.5. Linux Considerations
Section 2.6. Conclusion
Chapter 3. Installing Asterisk
Section 3.1. What Packages Do I Need?
Section 3.2. Obtaining the Source Code
Section 3.3. Compiling Zaptel
Section 3.4. Compiling libpri
Section 3.5. Compiling Asterisk
Section 3.6. Installing Additional Prompts
Section 3.7. Updating Your Source Code
Section 3.8. Common Compiling Issues
Section 3.9. Loading Zaptel Modules
Section 3.10. Loading libpri
Section 3.11. Loading Asterisk
Section 3.12. Directories Used by Asterisk
Section 3.13. Conclusion
Chapter 4. Initial Configuration of Asterisk
Section 4.1. What Do I Really Need?
Section 4.2. Working with Interface Configuration Files
Section 4.3. FXO and FXS Channels
Section 4.4. Configuring an FXO Channel
Section 4.5. Configuring an FXS Channel
Section 4.6. Configuring SIP
Section 4.7. Configuring Inbound IAX Connections
Section 4.8. Configuring Outbound IAX Connections
Section 4.9. Debugging
Section 4.10. Conclusion
Chapter 5. Dialplan Basics
Section 5.1. Dialplan Syntax
Section 5.2. A Simple Dialplan
Section 5.3. Adding Logic to the Dialplan
Section 5.4. Conclusion
Chapter 6. More Dialplan Concepts
Section 6.1. Expressions and Variable Manipulation
Section 6.2. Dialplan Functions
Section 6.3. Conditional Branching
Section 6.4. Voicemail
Section 6.5. Macros
Section 6.6. Using the Asterisk Database (AstDB)
Section 6.7. Handy Asterisk Features
Section 6.8. Conclusion
Chapter 7. Understanding Telephony
Section 7.1. Analog Telephony
Section 7.2. Digital Telephony
Section 7.3. The Digital Circuit-Switched Telephone Network
Section 7.4. Packet-Switched Networks
Section 7.5. Conclusion
Chapter 8. Protocols for VoIP
Section 8.1. The Need for VoIP Protocols
Section 8.2. VoIP Protocols
Section 8.3. Codecs
Section 8.4. Quality of Service
Section 8.5. Echo
Section 8.6. Asterisk and VoIP
Section 8.7. Conclusion
Chapter 9. The Asterisk Gateway Interface (AGI)
Section 9.1. Fundamentals of AGI Communication
Section 9.2. Writing AGI Scripts in Perl
Section 9.3. Creating AGI Scripts in PHP
Section 9.4. Writing AGI Scripts in Python
Section 9.5. Debugging in AGI
Section 9.6. Conclusion
Chapter 10. Asterisk for the Über-Geek
Section 10.1. Festival
Section 10.2. Call Detail Recording
Section 10.3. Customizing System Prompts
Section 10.4. Manager
Section 10.5. Call Files
Section 10.6. DUNDi
Section 10.7. Conclusion
Chapter 11. Asterisk: The Future of Telephony
Section 11.1. The Problems with Traditional Telephony
Section 11.2. Paradigm Shift
Section 11.3. The Promise of Open Source Telephony
Section 11.4. The Future of Asterisk
Appendix A. VoIP Channels
Section A.1. IAX
Section A.2. SIP
Appendix B. Application Reference
AbsoluteTimeout( )
AddQueueMember( )
ADSIProg( )
AgentCallbackLogin( )
AgentLogin( )
AgentMonitorOutgoing( )
AGI( )
AlarmReceiver( )
Answer( )
AppendCDRUserField( )
Authenticate( )
Background( )
BackgroundDetect( )
Busy( )
CallingPres( )
ChangeMonitor( )
ChanIsAvail( )
CheckGroup( )
Congestion( )
ControlPlayback( )
Curl( )
Cut( )
DateTime( )
DBdel( )
DBdeltree( )
DBget( )
DBput( )
DeadAGI( )
Dial( )
DigitTimeout( )
Directory( )
DISA( )
DumpChan( )
DUNDiLookup( )
EAGI( )
Echo( )
EndWhile( )
ENUMLookup( )
Eval( )
Exec( )
ExecIf( )
FastAGI( )
Festival( )
Flash( )
ForkCDR( )
GetCPEID( )
GetGroupCount( )
GetGroupMatchCount( )
Goto( )
GotoIf( )
GotoIfTime( )
Hangup( )
HasNewVoicemail( )
HasVoicemail( )
IAX2Provision( )
ImportVar( )
LookupBlacklist( )
LookupCIDName( )
Macro( )
MailboxExists( )
Math( )
MeetMe( )
MeetMeAdmin( )
MeetMeCount( )
Milliwatt( )
Monitor( )
MP3Player( )
MusicOnHold( )
NBScat( )
NoCDR( )
NoOp( )
Park( )
ParkAndAnnounce( )
ParkedCall( )
PauseQueueMember( )
Playback( )
Playtones( )
Prefix( )
PrivacyManager( )
Progress( )
Queue( )
Random( )
Read( )
RealTime
RealTimeUpdate( )
Record( )
RemoveQueueMember( )
ResetCDR( )
ResponseTimeout( )
RetryDial( )
Ringing( )
SayAlpha( )
SayDigits( )
SayNumber( )
SayPhonetic( )
SayUnixTime( )
SendDTMF( )
SendImage( )
SendText( )
SendURL( )
Set( )
SetAccount( )
SetAMAFlags( )
SetCallerID( )
SetCallerPres( )
SetCDRUserField( )
SetCIDName( )
SetCIDNum( )
SetGlobalVar( )
SetGroup( )
SetLanguage( )
SetMusicOnHold( )
SetRDNIS( )
SetVar( )
SIPAddHeader( )
SIPDtmfMode( )
SIPGetHeader( )
SoftHangup( )
StopMonitor( )
StopPlaytones( )
StripLSD( )
StripMSD( )
SubString( )
Suffix( )
System( )
Transfer( )
TrySystem( )
TXTCIDName( )
UnpauseQueueMember( )
UserEvent( )
Verbose( )
VMAuthenticate( )
VoiceMail( )
VoiceMailMain( )
Wait( )
WaitExten( )
WaitForRing( )
WaitForSilence( )
WaitMusicOnHold( )
While( )
Zapateller( )
ZapBarge( )
ZapRAS( )
ZapScan( )
Appendix C. AGI Reference
ANSWER
CHANNEL STATUS
DATABASE DEL
DATABASE DELTREE
DATABASE GET
DATABASE PUT
EXEC
GET DATA
GET FULL VARIABLE
GET OPTION
GET VARIABLE
HANGUP
NOOP
RECEIVE CHAR
RECORD FILE
SAY ALPHA
SAY DATE
SAY DATETIME
SAY DIGITS
SAY NUMBER
SAY PHONETIC
SAY TIME
SEND IMAGE
SEND TEXT
SET AUTOHANGUP
SET CALLERID
SET CONTEXT
SET EXTENSION
SET MUSIC ON
SET PRIORITY
SET VARIABLE
STREAM FILE
TDD MODE
VERBOSE
WAIT FOR DIGIT
Appendix D. Configuration Files
Section D.1. modules.conf
Section D.2. adsi.conf
Section D.3. adtranvofr.conf
Section D.4. agents.conf
Section D.5. alarmreceiver.conf
Section D.6. alsa.conf
Section D.7. asterisk.conf
Section D.8. cdr.conf
Section D.9. cdr_manager.conf
Section D.10. cdr_odbc.conf
Section D.11. cdr_pgsql.conf
Section D.12. cdr_tds.conf
Section D.13. codecs.conf
Section D.14. dnsmgr.conf
Section D.15. dundi.conf
Section D.16. enum.conf
Section D.17. extconfig.conf
Section D.18. extensions.conf
Section D.19. features.conf
Section D.20. festival.conf
Section D.21. iax.conf
Section D.22. iaxprov.conf
Section D.23. indications.conf
Section D.24. logger.conf
Section D.25. manager.conf
Section D.26. meetme.conf
Section D.27. mgcp.conf
Section D.28. modem.conf
Section D.29. musiconhold.conf
Section D.30. osp.conf
Section D.31. oss.conf
Section D.32. phone.conf
Section D.33. privacy.conf
Section D.34. queues.conf
Section D.35. res_odbc.conf
Section D.36. rpt.conf
Section D.37. rtp.conf
Section D.38. sip.conf
Section D.39. sip_notify.conf
Section D.40. skinny.conf
Section D.41. voicemail.conf
Section D.42. vpb.conf
Section D.43. zapata.conf
Section D.44. zaptel.conf
Appendix E. Asterisk Command-Line Interface Reference
!
abort halt
Section E.1. add
Section E.2. agi
Section E.3. database
Section E.4. iax2
Section E.5. indication
Section E.6. logger
Section E.7. meetme
Section E.8. pri
Section E.9. remove
Section E.10. restart
Section E.11. set
Section E.12. show
Section E.13. sip
Section E.14. stop
Section E.15. zap
Colophon
About the Authors
Colophon
Index
SYMBOL
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Index
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A
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F
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I
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M
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Q
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Y
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Z
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Variable Bitrate (VBR) codecs
variable manipulation
variables
AstDB, setting
ImportVar( ) application
Macro( ) application
reading from STDIN with fgets function
sent by Asterisk to AGI script at startup
2nd
sent by Asterisk to AGI script on startup
variables, using in dialplan
adding variables to dialplan
channel variables
environment variables
global variables
VERBOSE command
Verbose( ) application
verbosity, setting level for debugging messages
VIA-based motherboards, compiling Asterisk on
video
video camera connected to PC, live chats through
video components (built-in) on motherboards
video-conferencing
IP transport mechanism (H.323)
Virtual Private Network (VPN), use with IAX
VMAuthenticate( ) application
voice menus, creation with Background( )
Voice of Asterisk
voice prompts for Asterisk, sounds/ directory
voice, high-fidelity
voice-compression algorithms
voice-messaging, uniting with text messaging
voicemail
accessing
adding to dialplan
applications
creating mailboxes
dial-by-name directory
VoiceMail( ) application
2nd
voicemail.conf file
2nd
voicemail/ directory
VoiceMailMain( ) application
2nd
Voicetronix, analog cards
VoIP (Voice over IP)
2nd
access to, for legacy PBX
alternative route to an extension number or PSTN telephone number
Asterisk and
register statements
users, peers, and friends
bottleneck engineering
codecs
echo
Free World Dialup (FWD) service provider
gateways providing access to PSTN circuits
mobility with Wi-Fi
need for protocols
packet-switched networks
proprietary protocols
protocols
H.323
IAX
MGCP
protocols in use today
Quality of Service (QoS)
best effort method and
DiffServ
guaranteed service
TCP, UDP, and SCTP
Quality of Service, challenges to
Session Initiation Protocol (SIP)
SIP and IAX protocols
spam
Zapata Telephony Project
voltage
AC and DC, in analog phones
boosting for telephone during ringing
VPN (Virtual Private Network), use with H.323 protocol
Asterisk