Voicemail DTMF not recognized from desk phone but works from softphone

[Callinectes]

I have configured multiple desk phones on 2 different 3CX instances and in all situations the voicemail system (and I assume any other direct dialed IVR functionality) does not recognize key presses from the desk phones but there is no problem when accessing from the softphone. The desk phones are Polycom VVX 501s that have not been modified in any way, other than to add a dial plan (digit map), and are running firmware 6.3.0.14929. When calling out to an external IVR via a SIP Trunk the DTMF (key presses) function as expected. I do not see any way to modify the DTMF mode of the Polycom VVX 501 but would expect it to work right out of the box. I also don't see any way to modify the 3CX DTMF settings. FYI - the phones are set to ulaw. Any help or advice is appreciated and thanks in advance!

 

[leejor]

See if this is applicable to your model...
https://community.polycom.com/t5/Vo...end-DTMF-to-an-IVR-system-or-how-to/td-p/4237

 

[Callinectes]

See if this is applicable to your model...
https://community.polycom.com/t5/Vo...end-DTMF-to-an-IVR-system-or-how-to/td-p/4237

Thank you for the info and it may be relevant. I would think that for a supported phone I wouldn't have to make any adjustments such as this for something so simple?

 

[Callinectes]

So, as it turns out, enabling the setting "PBX Delivers Audio" seems to have corrected this issue. I need to do further testing, however.

 

[leejor]

You didn't say if the sets were at the same location as the server, or using STUN, which may be relevant. I'm going to assume , it's the latter.

 

[Callinectes]

The server is hosted in M$ Azure, so you are correct, they are remote using STUN.

 

[Callinectes]

Just a quick update on this. It appears that changing the "PBX Delivers Audio" option for each extension to enabled solved this problem and has presented no other problems, yet. I will update again if there are any anomalies caused by this change.

 

[leejor]

That option will usually fix audio issues on calls between remote STUN sets, at one location, as it forces audio back to the PBX then back again, to the other set, but, on a call going to the PBX anyway it should not make a difference. That said, it may indicate an issue with the method, and/or the Codec being used if DTMF is being sent In-Band. You could leave as is, as long as it continues to work, troubleshoot further, or consider an SBC for that site, at some point.