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Tesira DTMF tone duration

This article explains how to modify DTMF tone duration in the Biamp Tesira for POTS and VoIP systems.

DTMF tone duration

Sometimes, when dialing in to a voice mail system or conference bridge the default DTMF tone length is too short to consistently trigger the remote system. Biamp’s dialer properties settings allow you to modify the duration of the DTMF tones.

If DTMF tones are not registering you can try making the DTMF On Time longer, test in 50ms increments. (Be sure to also test this when the Wait for Dial Tone option is set to No.)

If tones are being received twice when dialing, try extending the DTMF Off Time to give a longer pause between digits, again, test in 50ms increments.

  • Tone On Duration (ms) or DTMF On Time (ms) sets the length of time the DTMF tone will be generated.
  • Tone Off Duration (ms) or DTMF Off Time (ms) sets the length of the pause between DTMF digits.


Examples of where to find the settings for Tesira STC-2 and SVC-2 are shown below.

Tesira - STC-2 - Analog Dialer

For an STC-2 card, the DTMF tone duration can be changed from the Property Sheet of the TI Control/Status block.  These settings can only be accessed while the software is disconnected from the Tesira system.

DTMF Tone Length Tesira POTS.PNG

Tesira - SVC-2 - VoIP

For an SVC-2 card, the DTMF tone duration can be changed from the Control Dialog of the VoIP Control/Status block.

DTMF Tone Length Tesira VoIP.PNG