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DTMF, continuous and generic tones

There are three types of tones that can be detected or generated using the Dialogic^® Diva^® SDK:  DTMF tones, continuous tones and generic tones.

DTMF tones are the familiar dialing tones generated by touch-tone telephones. Dialogic^® Diva^® Media Boards can generate DTMF tones and send them over the line to a remote user or application, and can also interpret tones on the line and report these to an application. No DSPs are needed to support DTMF functionality, so DTMF functionality is available on all Diva Media Boards. Diva Media Boards can detect standard DTMF tones 0-9, A, B, C, D, * and # as well as MF tones, which have different pairs of frequencies from DTMF.  Example functions: DivaReportDTMF, DivaSendDTMF.

Continuous tones include Fax tones (CED and CNG), modem tones, busy tone, ring tone, SIT tones, etc. A list of continuous tones can be found in the Dialogic Diva SDK documentation and in the DSSDK.H file included with the Diva SDK. Most tones can be generated as well as interpreted, but a few can only be interpreted. Continuous tones are only supported on Diva Media Boards equipped with DSPs.  Continuous tone detection is not available with Dialogic^® Host Media Processing (HMP) Software or Dialogic^® Diva^® softIP Software.  Example functions: DivaReportTones, DivaSendContinuousTone, DivaStopContinuousTone.

Note that voice activity detection (VAD) is also implemented using continuous tones; speech is reported as a special tone called DivaHumanSpeech.

Generic Tones:  Diva Media Boards with DSPs also have functions to generate and interpret 'generic tones' (these functions are not available in Dialogic^® Host Media Processing (HMP) Software or Dialogic^® Diva^® softIP Software).  A generic tone can either be a single tone or a pair of tones, so that you can generate tones of arbitrary frequency and length, and you can also program a Diva Media Board to listen for custom tones or tone pairs.  The generic tone detector can be useful for applications such as listening for PBX disconnect tones or answering machine tones.  Example functions: DivaDetectSingleTone, DivaDetectDualTone.

For more information, please consult the Dialogic Diva SDK Documentation.

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See also:
SDK: Change DTMF detection sensitivity