one more question about ;dtmfmode=auto account parameter

[juha-h]

Wiki https://github.com/baresip/baresip/wiki/Accounts#dtmfmode tells about ;dtmfmode=auto value

auto: It depends on the remote SDP which method is used. If there is an SDP format with name "telephone-event" then inbound DTMF is used, otherwise SIP INFO.

In the latter case, what happens if peer does not list INFO in its Allow header? Is it so that then baresip does not send DTMF keys?

[juha-h]

If remote party of the call does not advertise telephone-event nor INFO method, can baresip local party of the call somehow learn that the remote party is not able to receive DTMF?

[cspiel1]

Currently, baresip does not consider this option. In this case I am pretty sure, that it will ignore the Allow header and send a SIP INFO.

[juha-h]

I didn't find in struct call a field that would contain a list of Allow header tags. When call is established and peer has included Allow header in INVITE or 200 OK, then such a list could be constructed. Once done, ua would know if sending INFO makes sense. INFO can be sent if allow list is empty or contains INFO tag.