Intermittent DTMF (3CX 15.5.10244.4)

[st1172]

I can call the same IVR 10 times. It's hit or miss how many times will work or fail, but it is not consistent. Our staff makes hundreds of outbound calls each day and they are having issues with many different IVRs.

Wireshark shows the desk phones and 3CX clients are ALWAYS sending DTMF to 3CX.

Wireshark also shows that 3CX is NOT ALWAYS passing DTMF to the carrier. When the capture shows DTMF, the IVR works- when it does not show DTMF the IVR does not work.

I've done research and learned basically what you give 3CX for DTMF is what it passes. I've tried inband, RFC2833, and INFO methods on the Cisco desk phones we use and 3CX app with no change. There do not appear to be settings in 3CX for DTMF manipulation.

Anybody else running into this in the latest update? Ideas for other things to check?

Thanks everyone!

 

[YiannisH_3CX]

Hello @st1172

We haven't had any report with DTMF relating to the latest build in particular so i would recommend checking that the phones are provisioned correctly and the firewall checker passes the test. If everything looks OK and since you can replicate the issue then i would recommend contacting our support department so they can take a look at the issue. You can create a ticket either via a reseller or directly from here: https://www.3cx.com/ordering/pricing/
Support procedures can be found here: https://www.3cx.com/ordering/

 

[st1172]

@YiannisH_3CX

Looking at the support procedures it doesn't appear we'd get help as we are using non-standard provisioning templates with legacy phones, which is why I asked here in the forum. We've been using the exact same setup for at least a year and noticed zero DTMF issues until the latest build. Wireshark confirms the phones sending RFC2833 DTMF to 3CX, and 3CX intermittently NOT forwarding that to the carrier. We have the firewall locked down as it has been for over a year without issue. While I can certainly make all the exceptions necessary to pass the firewall checker, I'm not sure what would have changed in the latest service pack to cause this issue. (Certainly nothing I've changed, as we've only added and removed extensions in the past 12 months.)