Using a Cisco Pro Codec with 11.20 or higher we lose RS232 strings being received for Incoming Calls and DMTF tones don't work as well.
Here is what we have changed in the past to get issues resolved but recently these issues are showing up again.
1. Conference ActiveControl Mode: from Auto to Off;
2. Conference FarEndControl Mode: from On to Off;
3. Conference FarEndControl SignalCapability: from On to Off;
4. Conference MicUnmuteOnDisconnect Mode: from On to Off;
5. Conference MultiStream Mode: from Auto to Off;
6. Logging Internal Mode: from On to Off;
7. NetworkServices CDP Mode: from Off to On;
8. Peripherals Profile TouchPanels: from NotSet to 0.
9. Reboot Cisco VTC.
