DTMF Tones Issue in Call Center

[Delandro Omar]

Hi everyone,

I am facing a critical issue in our Call Center where IVR DTMF tones are no longer being recognized when customers attempt to select the available options. This functionality was working correctly last week but has suddenly stopped functioning without any apparent changes on our side.

The carriers have also confirmed that no modifications have been made on their end.

I would greatly appreciate your help in identifying and resolving the root cause of this issue as quickly as possible.

Best regards,

Delandro Omar

[Jonathan Schulenberg]

You provided zero information about your environment, config, or what you have already checked.

Based on the label you chose for the post, I’m assuming CCX. It doesn’t support Rfc2833 DTMF so the gateway needs to be offering out-of-band toward CUCM so it can interwork. Assuming CUBE, the command is dtmf-relay rtp-nte sip-kpml

If that doesn’t work you’ll need to start looking at logs/debugs. Personally, I would start on CUBE with SIP debugs and maybe a packet capture if you’re not seeing the KPML traffic to understand if CUBE even sees the RFC2833 RTP packets.

[Elliot Dierksen]

I agree with @Jonathan Schulenberg on this. Start with your gateways including what kind, the version, and what type of PSTN connection you have. Does DTMF work when outside callers get to Unity voicemail (assuming you have that)? What version of CUCM and UCCX? More information is better for troubleshooting. Speaking as someone who has been an escalation point for years, bringing the information needed to diagnose the problem and describing what you have done to troubleshoot or resolve the problem will make me much more interested in assisting than a vague "it doesn't work".