Dial pad not working when dialing DTMF extension

When using the dial pad for extensions or automated phone menus, you may encounter a situation where the system receives incorrect or duplicate inputs, for example pressing 1 might register as 11, or entering an extension like 123 might come through as 112233. This typically happens when DTMF tones (Dual Tone Multi-Frequency signals) are being inadvertently picked up and retransmitted by your microphone.

What Is DTMF?

Dual Tone Multi-Frequency (DTMF) is the signaling method used by touch-tone phones to send numeric input. Each key press generates two distinct audio tones that tell the phone system which number was pressed. When you dial an extension or select a menu option, those tones are transmitted digitally to the remote system to guide call routing.

In modern VoIP and WebRTC systems, DTMF tones are transmitted as digital audio packets, not traditional analog signals. However, because these tones are still audible, they can sometimes be picked up by your microphone, causing duplicate or incorrect tone entries.

Symptoms

You may notice one or more of the following:

• Automatic systems respond incorrectly when you press dial pad numbers.
• Input appears duplicated (for example, pressing 1 results in 11).
• Extensions or menu options are unrecognized or routed incorrectly.

Causes

DTMF tones are audio-based signals that can be mistakenly re-captured by your microphone if your speaker or headset volume is high. This creates an audio feedback loop, where the DTMF tone sent by your system is also heard and retransmitted as part of your live microphone input.

This results in:

• Multiple or distorted tone signals being received.
• Incorrect menu navigation or failed extension entries.

Occasionally, routing changes (such as staff reassignments or department changes) can also cause unexpected extension results. Not every incorrect routing is caused by DTMF interference.

Troubleshooting Steps

Follow these steps to resolve or reduce DTMF-related issues:

1. Mute your microphone while entering digits. You can do this by clicking the Mute button in the RingDNA Dialer or toggling your hardware microphone switch.

2. Lower your headset or speaker volume. This reduces the chance that DTMF tones are re-captured by your microphone.

3. Use a noise-canceling headset. These devices minimize feedback loops and suppress tone leakage.

4. Confirm the extension routing. If extensions have recently changed, verify the correct destination through your internal directory.

5. Restart your browser or dialer session. WebRTC-based audio sessions can sometimes benefit from a clean restart if tone transmission is inconsistent.

Contact Support

If you continue experiencing issues, please Contact our Support Team:

1. Submit a call report in the RingDNA Dialer (if you have not already done so)

   • Categorize the call as Other.

   • Include as many related call reports as possible.

   • In the Note field, include:

     • What number you entered
     • What number the system received
     • A brief description of what happened

2. Contact our Support Team for additional troubleshooting or to share example recordings.

Technical Insight

In WebRTC environments, DTMF tones can be sent either in-band (as part of the audio stream) or out-of-band (as separate signaling messages). Out-of-band transmission is more reliable but depends on carrier and browser support. If tones are misinterpreted, it is often due to echo feedback rather than signaling faults, and can usually be corrected through audio settings or headset configuration.