This section is a comprehensive description of the applications available for use in the dialplan (/etc/asterisk/extensions.conf). To use an application, the module to which it belongs must be loaded; this is configured in the [modules] section of /etc/asterisk/modules.conf with autoload=yes or explicitly with load => app_applicationname.so. You can see which modules and applications are available in Asterisk with by entering show applications or show application application_name (Asterisk 1.2) and core show applications oder core show application application_name (Asterisk 1.4).

Take care not to confuse applications or commands with functions. When required, functions are called within commands in the dialplan. "Application" is perhaps too expansive a term but it is the convention in Asterisk when referring to dialplan commands.

It is often possible to omit parameters entirely. In those cases, it is still necessary to include the comma delimiter to establish that a parameter is empty or not provided (i.e. that the default value should be used). For example:

exten => s,1,Dial(IAX2/User:password@example.com/123,,tT)

In general, if an application exits with an error it will return -1, if successful it returns a 0. A return value of -1 means that Asterisk will hang up the channel without passing it along the dialplan.

Anyone who has used Asterisk for some time already might wonder why one or another application is not included here. The missing applications have been deprecated in Asterisk 1.2 and have ceased to exist altogether in Asterisk 1.4. The corresponding functions which replace them can be found in Appendix C, Functions in the dialplan. The diff output of the built-in help files provided is always shown from the newer 1.4 to the older 1.2.

In the examples the arbitrarily chosen extension 123 and priority 1 are used, just for the purposes of illustration.

Before Asterisk 1.2, many applications jumped to priority n+101, if present, in case of an error (where n is the current priority). This old behavior (called "priority jumping") can be re-enabled with the option j (jump) for some commands or globally via the parameter priorityjumping=yes in the [general] section of extensions.conf. This method, however, is now deprecated. The objectives once met by priority jumping are now achieved by calling defined channel variables, which are considerably more powerful.

To enhance the utility of this book as a reference, the applications are listed in alphabetical order. They also can be arranged into logical categories, shown here:

Call handling (pick-up, transfer, hang-up, ...)

the section called “Answer()” - Answer

the section called “Busy()” - Signal busy to caller

the section called “ChanIsAvail()” - Check to see if a channel is available

the section called “ChannelRedirect()” - Redirect a channel to another extension and/or priority

the section called “Congestion()” - Signal congestion to caller

the section called “Dial()” - Initiate a call to a channel / connect to a channel

the section called “DISA()” - DISA (Direct Inward System Access)

the section called “FollowMe()” - "follow me" function

the section called “Hangup()” - Hang up

the section called “Page()” - Page multiple devices

the section called “Park()” - Park call

the section called “Pickup()” - Call pickup

the section called “RetryDial()” - Dial() with auto-redial

the section called “Ringing()” - Signal ringing to caller

Flow control and timeouts

the section called “ContinueWhile()” - Jump to the beginning of a While() loop

the section called “EndWhile()” - End a While() loop

the section called “Exec()” - Launch an application

the section called “ExecIf()” - Conditional launch of an application

the section called “ExecIfTime()” - Time conditional launch of an application

the section called “ExitWhile()” - Break a While() loop

the section called “Gosub()” - Go to a subroutine

the section called “GosubIf()” - Conditional Gosub()

the section called “Goto()” - Go to another priority, and/or extension and/or context

the section called “GotoIf()” - Conditional Goto()

the section called “GotoIfTime()” - Time conditional Gosub()

the section called “Random()” - Go to a random entry in the dialplan

the section called “Return()” - Return to priority from which Gosub() and GosubIf() was called

the section called “TryExec()” - Attempt to launch an application and get the return code

the section called “While()” - Start a while loop

Macros

the section called “Macro()” - Call a macro

the section called “MacroExclusive()” - Call a macro only once at a time

the section called “MacroExit()” - Exit from the macro

the section called “MacroIf()” - Conditional call of a macro

Caller detection, presentation and handling

the section called “CallingPres()” - Change the caller presentation on PRI circuits

the section called “LookupBlacklist()” - Look up the caller ID in the blacklist

the section called “LookupCIDName()” - Look up the caller ID name in the database

the section called “PrivacyManager()” - Request that the caller enter the originating number if no caller ID is available

the section called “SetCallerPres()” - Set the caller ID independently of the calling channel

the section called “SoftHangup()” - Request a hangup

the section called “Zapateller()” - Block telephone solicitations

Call detail records (CDRs)

the section called “AppendCDRUserField()” - Append a value to the CDR 'user' field

the section called “ForkCDR()” - Creates an additional CDR for the current call

the section called “NoCDR()” - Disable CDR for this call

the section called “ResetCDR()” - Resets the current CDR

the section called “SetAMAFlags()” - Set AMA flags

the section called “SetCDRUserField()” - Sets the CDR 'user' field

Voicemail

the section called “Directory()” - Provide the "Dial-by-Name" directory

the section called “mailboxExists()” - Checks if the mailbox exists

the section called “VoiceMail()” - Voicemail engine

the section called “VoiceMailMain()” - Voicemail retrieval engine

the section called “VMAuthenticate()” - Authenticates the user using user information contained in voicemail.conf

Conferences

the section called “MeetMe()” - MeetMe conference

the section called “MeetMeAdmin()” - Administer a MeetMe conference

the section called “MeetMeCount()” - Provides a count of the participants in a MeetMe conference

Variable handling

the section called “ImportVar()” - Import a variable from a channel

the section called “Read()” - Read digits from a user into a variable

the section called “ReadFile()” - Read a file into a variable

the section called “RealTime()” - Read a value from the realtime system into a variable

the section called “RealTimeUpdate()” - Change a variable in the realtime system

the section called “Set()” - Set a channel variable

the section called “SetGlobalVar()” - Set a global variable

Sound files & Music-on-Hold

the section called “Background()” - Play a sound file while proceeding to the next priority

the section called “BackgroundDetect()” - Background() with sound detection

the section called “ControlPlayback()” - Playback() with user playback controls

the section called “DateTime()” - Say the date and time

the section called “Echo()” - Echo received sound to the user

the section called “Festival()” - Read text as speech using the Festival Text-To-Speech engine

the section called “Milliwatt()” - Provide a constant 1004 Hz tone at 0 db

the section called “MP3Player()” - Play an mp3 file or stream

the section called “MusicOnHold()” - Play music-on-hold

the section called “NBScat()” - Play an NBS stream

the section called “Playback()” - Play a sound file

the section called “Playtones()” - Play a tone

the section called “Progress()” - Provide the calling channel with in-band progress sounds

the section called “SayAlpha()” - Spell out an alphanumeric string

the section called “SayDigits()” - Say digits

the section called “SayNumber()” - Say a number

the section called “SayPhonetic()” - Spell out a string using the phonetic alphabet

the section called “SayUnixTime()” - Say the Unix time

the section called “SetMusicOnHold()” - Set the Music-on-Hold class

the section called “StopPlaytones()” - Stops Playtones()

Recording and Monitoring

the section called “AgentMonitorOutgoing()” - Record the outgoing calls of a call agent

the section called “ChangeMonitor()” - Changes the filename prefix of a specific channel for Monitor()

the section called “ChanSpy()” - Eavesdrop on an active channel

the section called “Dial()” - Record a conversation (when used with option w or W)

the section called “Dictate()” - A virtual dictation machine

the section called “ExtenSpy()” - Eavesdrop on an active channel, and whisper to the originating caller

the section called “MixMonitor()” - Like Monitor() but mixes both legs into a single file

the section called “Monitor()” - Records each leg (incoming and outgoing) of a call in separate files

the section called “PauseMonitor()” - Pauses recording

the section called “Record()” - Records only incoming audio

the section called “StopMonitor()” - Stop recording with Monitor()

the section called “UnpauseMonitor()” - Resumes recording

the section called “ZapBarge()” - Eavesdrop on a ZAP channel

the section called “ZapScan()” - Eavesdrop on Zap channels and switch easily between them

Database operations

the section called “DBdel()” - Erase a record from the database

the section called “DBdeltree()” - Erase a branch from the database

General

the section called “Authenticate()” - Authenticate a user

the section called “SendDTMF()” - Send DTMF tones

the section called “SendImage()” - Send an image

the section called “SendText()” - Send text

the section called “SendURL()” - Send a URL

the section called “Transfer()” - Transfer a call

the section called “VMAuthenticate()” - Authenticate a user configured in voicemail.conf

the section called “Wait()” - Wait for a specified time

the section called “WaitExten()” - Wait for the user to dial an extension for specified time

the section called “WaitForRing()” - Wait for ring

the section called “WaitForSilence()” - Wait for silence

the section called “WaitMusicOnHold()” - Wait while providing music-on-hold to caller

External applications

the section called “AGI()” - Execute an AGI script

the section called “DeadAGI()” - AGI() on an inactive channel

the section called “DumpChan()” - Dump information about a channel to the CLI

the section called “EAGI()” - See AGI()

the section called “ExternalIVR()” - Call an external IVR generator

the section called “FastAGI()” - AGI() on another server

the section called “Log()” - Log a message at the specified verbosity level

the section called “Macro()” - Execute a macro

the section called “NoOp()” - No operation; write debugging information to the CLI

the section called “Perl()” - res_perl is like mod_perl for Apache, only for Asterisk

the section called “PHP()” - res_php is like mod_php for Apache, only for Asterisk

the section called “Read()” - Read digits from a user into a variable

the section called “System()” - Execute a shell command

the section called “TrySystem()” - Like System(), but always returns 0

the section called “UserEvent()” - Send an event to the Manager interface

the section called “Verbose()” - Send a message to the CLI at the specified verbosity level

SIP

the section called “SIPdtmfMode()” - Change the SIP DTMF mode for a SIP originated call

the section called “SIPAddHeader()” - Add a SIP header for an outgoing call

ZAP

the section called “Flash()” - Send a flash-hook on a ZAP trunk

the section called “ZapBarge()” - Eavesdrop on a ZAP channel

the section called “ZapRAS()” - Enable RAS (Remote Access Server) on a ZAP ISDN channel

the section called “ZapScan()” - Eavesdrop on Zap channels and switch easily between them

Queues and call center functions

the section called “AddQueueMember()” - Dynamically add an interface to a queue

the section called “AgentCallbackLogin()” - Log-in a queue agent (with call back)

the section called “AgentLogin()” - Log-in a queue agent

the section called “AgentMonitorOutgoing()” - Record outgoing call of an agent

the section called “ParkAndAnnounce()” - Park a call and announce it

the section called “ParkedCall()” - Pick up a parked call

the section called “PauseQueueMember()” - Pause a queue member

the section called “Queue()” - Send a call to the queue

the section called “QueueLog()” - Write a message to the queue log

the section called “RemoveQueueMember()” - Remove an interface from the queue

the section called “UnpauseQueueMember()” - Resume a paused queue member

ADSI

the section called “ADSIProg()” - Load an ADSI script into an ADSI telephone device

the section called “GetCPEID()” - Request the ADSI-CPE-ID from an ADSI telephone device

Miscellaneous

the section called “AMD()” - Answering machine detection

the section called “AlarmReceiver()” - Receive and process alarm system events in Contact-ID format from an Ademco alarm panel

the section called “IAX2Provision()” - Provision an IAXy device

the section called “Morsecode()” - Send text as Morse code

the section called “SetTransferCapability()” - Set ISDN transfer capability

the section called “SMS()” - Send or receive SMS messages