Fresh 14 install with Asterisk 13.17.0. Cisco handset CP-8941 (SIP 9-2-3-5) everything up to date using CHAN SIP as that was how everything was setup before.
All working nicely except DTMF (re-install of setup due to borked upgrade) = i cannot manage voicemail or use remote menu systems.
The extension is set to RFC 2833 + NO nat + TCP preferred.
In the XML for the handset i have…
<preferredCodec>g711alaw</preferredCodec>
<dtmfAvtPayload>101</dtmfAvtPayload>
<dtmfDbLevel>6</dtmfDbLevel>
<dtmfOutofBand>avt</dtmfOutofBand>
I cannot find info to make sense of the above statements so if anyone has a pointer or some suggestions as to how to get DTMF working sensibly with this handset and FreePBX i would be happy.
If you need any more config or trace details to understand what is happening - ask and i will collect what is needed.
Everything else seems to be working nicely, very happy with the handset(s).