CUCM 7.1 and CP 7900 series no key press tone and DTMF.

[vantonenko]

Hello

There is a problem with Dial tone and DTMF on 7900 series phones on CUCM 7.1

Sometimes at any of the IP phones when phone get hook-of I hear dial tone but not hear key press tone when typing a number.

Phone can make and answer calls.
But when I call to IVR - DTMF not working.

In SDI trace I can view that key was pressed during the call, but actually addon dialing not works.

On other phones DTMF works.

After resetting CUCM this problem gone for a while, but returns on other phone.

Resetting the phone not helped.

Please, help me with this issue. I can't understand what might be the reason of this behavior, and how to troubleshoot this. Or is this a kind of bug?

All phones and lines has identical configurations, an using SIP trunk to get to the PSTN.

[Manish Gogna]

As you mentioned that the problem went away for a while after resetting cucm so it can be a bug or a MTP leakage issue. Since you are running cucm 7.1 you should at least be running the latest 7.1.5 version available on cisco.com and also upgrade the problematic phones to latest firmware. See if the issue persists and post the latest cucm sdi or sdl traces for a test call.

Manish

[vantonenko]

I sniffed streams with working and problem phone and noticed:

Stream of working phone:

Signal flow going through Subscriber, voice flow going through Publisher

Phone uses inband DTMF using changing of RTP Payload

CUCM uses this DTMF method too over SIP trunk.

Stream on problem phone:

Signal and voice flow over subscriber.

Phone uses Skinny OOB DTMF (Keypad Button Message)

CUCM does not send DTMF to SIP trunk. 

Now CUCM are restarted, problem is temporary gone.

[vantonenko]

I sniffed streams with working and problem phone and noticed:

Stream of working phone:

Signal flow going through Subscriber, voice flow going through Publisher

Phone uses inband DTMF using changing of RTP Payload

CUCM uses this DTMF method too over SIP trunk.

Stream on problem phone:

Signal and voice flow over subscriber.

Phone uses Skinny OOB DTMF (Keypad Button Message)

CUCM does not send DTMF to SIP trunk. 

Now CUCM are restarted, problem is temporary gone.