DTMF is not working for more then 65 calls.

[MD. JAKIR HOSSAIN]

When a customer dials DID numbers, After listening the greetings it is asked like to press 1 and 2 for the language selection or any other option.
This ivr dialed digit have no effect. It occurs when there are more then 65 cals on CUBE(VG). I have SIP trunk with IPTSP (provider).

[Jonathan Schulenberg]

You did not describe your environment at all (eg products, version, call path, etc) so this answer is a stab in the dark.

If the IVR is CCX you need a Cusco Media Group port to process DTMF for every concurrent call. I suggest over-provisioning the ports by 5-10% of your license count since they take a few seconds to reset.

If the IVR is CUC you likely have a DTMF interworking problem that is forcing CUCM to invoke an IOS software or hardware MTP. The correct solution to that scenario would be to fix the configuration issue causing the mismatch, not to add MTP capacity.