Hi,
Linphone supports DTMF using SIP INFO or RFC 4733.
Asterisk typically supports the same.
Maybe your Asterisk server is not set tup properly to perform DTMF.
I've been using Linphone on Android for many years as a secondary option, which I liked.
I successfully dial and receive calls.
I am hoping to use Linphone on my Android as a primary option and, in testing, have run into a problem.
My droid Linphone is connected to an Asterisk PBX.
I just noticed DTMF does not seem to be working in some cases (as mentioned, I can dial-out).
When I try to access voicemail the PBX doesn't seem to respond when I enter my mailbox number.
When I noticed this my next test was to try DTMF on another service. I called a customer support number and tried to use DTMF. That didn't work, either.
Can anyone please offer some suggestions on how I can get this working?