OOB DTMF issue

[DOM.RF NOC]

Hi!

I have following scheme:

SCCP IP Phone (as example 7971) > CUCM version 11.0 - SIP Trunk > SIP Dial-peer - GW 2811 12.4(24)T6 - FXO > Telco (PSTN)

The problem is that when i try to call from Cisco IP Phone to some IVR number through PSTN - dtmf does not work.

On CUCM i have following configuration:

1. Media Termination Point Required - off

2. DTMF Signaling Method - No preference

On 2811:

dial-peer voice 10 voip
session protocol sipv2
session target ipv4:<ip address of CUCM>
dtmf-relay sip-notify
codec g711ulaw

If i enable Media Termination Point Required on CUCM everything is working fine, but i don't want to do this.

Is it possible to make this scheme work without of using MTP resources?

Thank you!

[Chris Deren · Accepted solution]

Make are you have an inbound dial-peer as the one you posted would be an outbound dial-peer to CUCM only, you can simply add:

"incoming called-number ." to this dial peer. If that does not help try changing dtmf relay on the dial peer to "dtmf-relay rtp-nte sip-kpml".

[DOM.RF NOC]

Thank you, Chris!

Incoming dial-peer with "dtmf-relay rtp-nte sip-kpml" helped us.