We have implement IVR on our voice gateway 2921. It should work with incoming calls from PSTN through the SP's SIP-trunk. But the SP sends DTMF in band within g711. All calls to IVR are going through gateway to CCM and it forwards them back to gateway's dial-peer with IVR script if is after hours call.
As I understood there should be a MTP for recieve DTMF in band signals. So where it should be configured? On CCM or on the gateway?
Maybe I'm missing something.