Application Modules in Asterisk

Dialplan applications are used in extensions.conf to define the various actions that can be applied to a call. The Dial() application, for example, is responsible for making outgoing connections to external resources and is arguably the most important dialplan application.

Name	Purpose	Popularity/Status
`app_adsiprog`	Loads Analog Display Services Interface (ADSI) scripts into compatible analog phones	Insignificant
`app_alarmreceiver`	Supports receipt of reports from alarm equipment	Insignificant
`app_amd`	Detects answering machines	Unreliable
`app_authenticate`	Compares dual-tone multi-frequency (DTMF) input against a provided string (password)	Useful
`app_cdr`	Writes ad hoc record to CDR	Useful
`app_celgenuserevent`	Generates user-defined events for CEL	New
`app_chanisavail`	Checks the status of a channel	Unreliable
`app_channelredirect`	Forces another channel into a different part of the dialplan	Useful
`app_chanspy`	Allows a channel to listen to audio on another channel	Useful
`app_confbridge`	Provides conferencing (new version)	New—not fully featured yet
`app_controlplayback`	Plays back a prompt and offers fast forward and rewind functions	Useful
`app_dahdibarge`	Allows barging in on a DAHDI channel	Deprecated—see `app_chanspy`
`app_dahdiras`	Creates a RAS server over a DAHDI channel (no modem emulation)	Insignificant
`app_db`	Used to add/change/delete records in Asterisk’s built-in Berkeley database	Deprecated—see `func_db`
`app_dial`	Used to connect channels together (i.e., make phone calls)	Essential
`app_dictate`	Plays back a recording and offers start/stop functions	Useful
`app_directed_pickup`	Answers a call for another extension	Useful
`app_directory`	Presents the list of names from `voicemail.conf`	Useful
`app_disa`	Provides dialtone and accepts DTMF input	Useful
`app_dumpchan`	Dumps channel variables to Asterisk command-line interface (CLI)	Useful
`app_echo`	Loops received audio back to source channel	Useful
`app_exec`	Contains `Exec()`, `TryExec()`, and `ExecIf()`; executes a dialplan application based on conditions	Useful
`app_externalivr`	Controls Asterisk as with an AGI, only asynchronously	Useful
`app_fax`	Provides `SendFax()` and `ReceiveFax()`	Useful
`app_festival`	Enables basic text to speech using Festival TTS engine	Usable
`app_flash`	Performs a hook-switch flash on channels (primarily analog)	Useful
`app_followme`	Performs find me/follow me functionality based on `followme.conf`	Useful
`app_forkcdr`	Starts new CDR record on current call	Usable
`app_getcpeid`	Gets the ADSI CPE ID	Insignificant
`app_ices`	Sends audio to an Icecast server	Usable
`app_image`	Transmits an image to supported devices	Limited
`app_ivrdemo`	Sample application for developers	Insignificant
`app_jack`	Works with JACK Audio Connection Kit to share audio between compatible applications	Useful
`app_macro`	Triggers dialplan macros	Deprecated—see `GoSub()`
`app_meetme`	Provides multiparty conferencing	Useful—fully featured
`app_milliwatt`	Generates 1004-Hz tone for testing loss on analog circuits	Useful
`app_minivm`	Provides primitive functions to allow you to build your own voicemail application in dialplan	Usable
`app_mixmonitor`	Records both sides of a call and mixes them together	Useful
`app_morsecode`	Generates Morse code	Usable
`app_mp3`	Uses mpg123 to play an MP3	Insignificant
`app_nbscat`	Streams audio from Network Broadcast Stream (NBS)	Insignificant
`app_originate`	Allows origination of a call	Useful
`app_osplookup`	Performs Open Settlement Protocol (OSP) lookup	Usable
`app_page`	Creates multiple audio connections to specified devices for public address (paging)	Useful
`app_parkandannounce`	Enables automated announcing of parked calls	Usable
`app_playback`	Plays a file to the channel (does not accept input)	Useful
`app_playtones`	Plays pairs of tones of specified frequencies	Useful
`app_privacy`	Requests input of caller’s phone number if no CallerID is received	Insignificant
`app_queue`	Provides Automatic Call Distribution (ACD)	Useful
`app_read`	Requests input of digits from callers and assigns input to a variable	Useful
`app_readexten`	Requests input of digits from callers and passes call to a designated extension and context	Usable
`app_readfile`	Loads contents of a text file into a channel variable	Deprecated—see the `FILE()` function in`func_env`
`app_record`	Records received audio to a file	Useful
`app_rpt`	Provides a method to interface with an audio board for the `app_rpt` project	Limited
`app_sayunixtime`	Plays back time in specified format	Useful
`app_senddtmf`	Transmits DTMF to calling party	Useful
`app_sendtext`	Sends a text string to compatible channels	Insignificant
`app_setcallerid`	Sets CallerID on a channel	Deprecated—see`func_callerid`
`app_skel`	Sample application for developers	Useful
`app_sms`	Sends SMS message in compatible countries	Limited
`app_softhangup`	Requests hangup of channel	Useful
`app_speech_utils`	Provides utilities relating to speech recognition	Useful
`app_stack`	Provides `Gosub()`, `GoSubIf()`, `Return()`, `StackPop()`, `LOCAL()`, and `LOCAL_PEEK()`	Essential
`app_system`	Executes commands in a Linux shell	Useful
`app_talkdetect`	Similar to `app_background`, but allows for any received audio to interrupt playback	Useful
`app_test`	Client/server testing application	Usable
`app_transfer`	Performs a transfer on the current channel	Useful
`app_url`	Passes a URI to the called channel	Limited
`app_userevent`	Generates a custom event in the Asterisk Manager Interface (AMI)	Useful
`app_verbose`	Generates a custom event in the Asterisk CLI	Useful
`app_voicemail`	Provides voicemail	Essential
`app_waitforring`	Waits for a RING signaling event (not to be confused with RINGING); most likely unnecessary, as only `chan_dahdi` with analog channels where ringing is received (such as an FXO port) generates the RING signaling event	Insignificant
`app_waitforsilence`	Includes `WaitForSilence()` and `WaitForNoise()`; listens to the incoming channel for a specified number of milliseconds of noise/silence	Useful
`app_waituntil`	Waits until current Linux epoch matches specified epoch	Useful
`app_while`	Includes `While()`, `EndWhile()`, `ExitWhile()`, and `ContinueWhile()`; provides while-loop functionality in the dialplan	Useful
`app_zapateller`	Generates SIT tone to discourage telemarketers	Usable

Bridging Modules

Bridging modules are new in Asterisk 1.8: they perform the actual bridging of channels in the new bridging API. Each provides different features, which get used in different situations depending on what a bridge needs.

Name	Purpose	Popularity/Status
`bridge_builtin_features`	Performs bridging when utilizing built-in user features (such as those found in `features.conf`).	New
`bridge_multiplexed`	Performs complex multiplexing, as would be required in a large conference room (multiple participants). Currently only used by `app_confbridge`.	New
`bridge_simple`	Performs simple channel-to-channel bridging.	New
`bridge_softmix`	Performs simple multiplexing, as would be required in a large conference room (multiple participants). Currently only used by `app_confbridge`.	New