I am able to get the mid call DTMF features from mobile phones for SNR calls only when the call is originated from the mobile. By the features I mean hold, resume, conference and call park etc which are invoked by sending the appropriate combination of DTMF from the mobile phone.
I do not get these features when I receive the call on the mobile handset or when it is transferred from the IP Phone to the mobile phone. In this scenario any keys that are pressed send the DTMF tones directly as audio to the IP Phone and this is perhaps why the CUCM is not able to detect the tones and invoke the features.
Thanks for any help in advance.