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Wait for period of time while scanning for call progress tones


Waits for a a distinguishable call progress tone and then exits. Unlike a conventional scanner, this is not currently capable of scanning for modem carriers.


    • RINGING - Audible ringback tone

    • BUSY - Busy tone

    • SIT - Special Information Tones

    • VOICE - Human voice detected

    • DTMF - DTMF digit

    • FAX - Fax (answering)

    • MODEM - Modem (answering)

    • DIALTONE - Dial tone

    • NUT - UK Number Unobtainable tone

    • TIMEOUT - Timeout reached before any positive detection

    • HANGUP - Caller hung up before any positive detection


  • zone - Call progress zone. Default is the system default.

  • timeout - Maximum amount of time, in seconds, to wait for call progress or signal tones. Default is forever.

  • threshold - DSP threshold required for a match. A higher number will require a longer match and may reduce false positives, at the expense of false negatives. Default is 1.

  • options

    • f - Enable fax machine detection. By default, this is disabled.

    • v - Enable voice detection. By default, this is disabled.

See Also

Generated Version

This documentation was generated from Asterisk branch 18 using version GIT