How to troubleshoot DTMF issues in Switchvox

Owned by Nathaniel Halbrooks
Last updated: Oct 14, 2024 by Kelli Higdon
3 min read

Having trouble with callers being able to enter digits when dialing in?

When calls come into a system, the user can enter digits in an IVR to assist with routing.  These digits are called DTMF tones.  The reasons why the system might not detect these tones can vary from the provider that is sending the tones to the Switchvox system not detecting them properly. 

 

Before we continue on, we must first determine if the issue is internal or external to the Switchvox.  To do this, we need to call the IVR's extension number from an internal extension, that is an extension registered to the Switchvox on the same LAN as the Switchvox.  Is the issue reproducible?  If yes, then the issue is most likely the IVR configuration and you should double check to make sure:

  1. All actions are interruptible within the IVR

  2. Extension dialing is enabled within the IVR

  3. There is a direct path to the Listen for Options action within the IVR

 

If we cannot reproduce by dialing internally, then the issue is external to the Switchvox, i.e. provider, caller's cell phone, etc...

**For PRI, the first thing to check is to make sure the Relax DTMF setting is set to YES in the Manage > Channel Group > Bearer Channel section of your PRI setup.  If you are using PRI, set this to yes and then try to reproduce. 

**For SIP, please confirm with your provider what DTMF mode they recommend.  You should also test each of the DTMF mode settings in the VoIP provider section before moving on.

 

If still reproducible, then move on to the following troubleshooting steps:

  1. Let’s create a DTMF test IVR to record digits and play them back so we can get a consistent feedback of the digits we are entering and what the system is detecting.    In the IVR Editor, create an IVR called DTMF Test with two actions:

  • Record Digits (10 digits) and set the digits to be recorded in a variable.

  • Say Digits / Letters and choose the variable you just set the DTMF tones to be stored in.

  1. Create an IVR extension and assign it to the DTMF Test IVR.

  2. Dial the DTMF Test IVR internally to make sure it is working and that DTMF is working internally.

  3. Point a DID directly to the DTMF Test IVR so we can call in over your provider to confirm that the same digits that we are entering are being played back.  If the digits that you are entering are not being played back then the issue is with the call path over the provider and we need to get with your provider to confirm that these are the digits they are sending.

  4. If the digits over the DID are being relayed back correctly, then we want to move to the IVR that is reporting the issue.

  5. If the issue is not reproducible when dialing directly, but is in the IVR then we need to create a brand new IVR with only one interruptible sound and allow extension dialing so that we can attempt to reproduce the issue with a clean IVR.  If the issue can still be reproduced by calling into a clean IVR, please contact support with all of your testing information and we can help you further diagnose. 

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