CCX Get Digit Not Recognizing DTMF

[JohnBushong8071]

The first Get Digit step does not always recognize DTMF tones. If I enter the digits numerous times, it will finally recognize them. Other times, it recognizes on the first attempt. Step is using the # as a terminator.

Other Get Digit steps in this script have no issue.

Steps taken:

Rebuild script; rebuild CTI ports (from CCX); Rebuild Application

System: 11.5 (No SU installed) I know, I really should upgrade to SU10. This system is operating 4 applications with no agents.

[Elliot Dierksen]

What kind of device is calling this application (PSTN caller or IP phone)? Is the behavior the same for internal and external callers? Is there a play prompt prior to this get digit step that has its prompt marked an not interruptible? Are there play prompt or menu steps prior to this that are marked to clear the input buffer?

[JohnBushong8071]

Always calling from an IP phone.

I am using the prompt in the Get Digit step

The only steps before this are Accept and Wait 

The Get Digit does allow interruption and does clear the input buffer on failure

As stated, this step does work properly sometimes and will work after many attempts to input the same digits when it is failing.

[Elliot Dierksen]

If you build an application using the system auto attendant does DTMF work as expected? If it is also inconsistent then there is something outside of the script causing the issue. CCX only supports out of band DTMF, so that means it almost always needs an MTP for that purpose. Do the CTI ports have an MTP available via the MRGL? Are the CTI ports in a region that uses G.711 with the calling phone? CCX can support G.729 or G.711, but only codec is selected. CCX is almost always deployed using G.711, so if the calling phone is in a region where G.729 would be used then the CTI port would need a transcoder.

[JohnBushong8071]

The Region the phones use has codec G.711 so I did not have MRGL assigned on the CTI ports. I went ahead and assigned that (in CCX) and tested - same issue. There is only one MRGL on the UCM and it does have MTPs assigned. Required DTMF reception is set to Yes on the CTI ports.

[Elliot Dierksen]

OK. What about if you create an application using the system AA script?

[JohnBushong8071]

I'll have to check on that at a later time as I am not able to utilize Editor right now.

[Elliot Dierksen]

You don't need the editor to build an application with the system AA script.

[JohnBushong8071]

I just looked at the system and there is no default AA script in the script folder. 

[Jonathan Schulenberg]

“CCX only supports out of band DTMF, so that means it almost always needs an MTP for that purpose.”

As an aside, you should be able to avoid MTPs even with SIP so long as all of the dial-peers facing CUCM offer both KPML and RFC2833; CUCM will automatically subscribe to KPML If the other leg lacks RFC2833.

dtmf-relay rtp-nte sip-kpml

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/configuration/cube-book/dtmf-relay.html