Auto-Attendant not accepting user input

[aaronrusch]

We have a phone tree that instructs outside callers to input numbers to be routed to specific extensions, hunt groups, and/or voicemails. Out of nowhere about 9 months ago inputs stopped working to random callers at random times of day. They could call back and inputs would work, or call back and inputs would still not work. Again, this started happening of January of 2024 after working for a good 2 months.

Is this a common issue? How would one go about fixing this?

[Jonathan Schulenberg]

Not common for it to spontaneously stop working. Start with debugs of the SIP SBC to compare a working and non-working call. Are there differences in the DTMF relay?

[Nithin Eluvathingal]

This is not common. My guess is that the calls not working might be using a different path with incorrectly configured DTMF, causing intermittent issues. If all the calls are through the same gateway, as @Jonathan Schulenberg  mentioned, compare the working and non-working calls.

[Elliot Dierksen]

I agree with @Jonathan Schulenberg and @Nithin Eluvathingal that this is quite unusual. The SBC debugs will likely point you in the right direction. It seems most likely to me that one of the ITSP's along the path has made changes that are impacting DTMF. The intermittent nature of it is puzzling, but perhaps calls don't always take the same path.

[aaronrusch · Accepted solution]

Just wanted to follow up on the issue as we found the problem. Webex calling was working properly, the issue was with a local cellular provider. For whatever reason, users of said provider only occasionally had their button presses transmitted. Some calls worked, most didn't. The provider did not explain their fix, so that's all I can share. 

So if this happens to anyone in the future, check to see if only users from a certain provider are experiencing the issue.

Thanks for all your help!