Long Tones

While the default value of the DTMF tones is 100 msec, and the intent of this feature is to be able to extend the length of the tones, the length of the tone can be set in a range between 40 and 1000 msec.

Feature Description

Support for Long Tones enhances UCX operation when attempting to control third party devices like Door Phones that require a longer length of tone to enable accurate DTMF detection. This feature allows the adjustment of the length of tones generated when a DTMF button is pressed on an Infinity XSTIM or Nortel Unistim IP phone or any supported digital phone.


This functionality is enabled on a system-wide basis and is administered via the XSTIM Settings page.

To set the DTMF Tone length:

  1. Open UCX Administration
  2. From the PBX tab, select PBX Configuration
  3. From the left side column under Settings, select XSTIM Settings
  4. Scroll down to the Other XSTIM Settings
  5. If there is no empty field, then click Add Field
  6. In the left side of the empty field, enter the following text string: dtmf_tone_duration
  7. In the right side of the empty field, enter the length of tone you wish to generate in milliseconds. In the example below it is set as 200 ms
  8. Click the Submit Changes button

Verifying Configuration

You may verify the current value of the length of the DTMF tones being used on the UCX using Asterisk CLI capability on the PBX Tools page.

To verify the length of DTMF calls:

  1. Open UCX Administration
  2. From the PBX tab, select PBX Tools
  3. In the Command field enter ucx show settings
  4. Review the Other Settings section of the output for the value of DTMF tone duration