I have integration with mobile carrier using SIP. The current setup is the mobile carrier connected to asterisk A then this server is forwarding the call to another asterisk server B.
The problem is the server is not detecting the DTMF the user is entering when using Read().
If you are using a device with a SIM card, the mobile air interface doesn’t allow for DTMF to be sent to the mobile, as it is designed for human users of the audio.
I don’t believe an of the codecs used for mobile networks are suitable for inband DTMF and out of band signally is only supported in the outbound direction.