MGCP DTMF on SIP Phones

[Flo.Matalis]

Hi Experts,

CUCM: 11.5 SU4

GW: ISR 4331/bootflash:isr4300-universalk9.16.06.04.SPA.bin

Phone: 7841/sip78xx.12-1-1SR1-4

I am having issues with my DTMF on SIP phones. We are using MGCP.

On SCCP phones, DTMF is working. We already tried changing the DTMF relay options on Call Manager, reset MGCP service and tested, but still not working.

Any ideas please? Thank you. 

[Sreekanth Narayanan]

What's the DTMF type you've set on the gateway configuration on the CUCM?
Have you tried changing it to different values such as OOB?

[Sreekanth Narayanan]

You can take a look at this document for some tips. https://community.cisco.com/t5/service-providers-blogs/chalk-talk-troubleshooting-dtmf-relay-over-mgcp/ba-p/3098846

[Mohammed al Baqari]

During active call, check the call legs using show call active voice | i
Dtmf and see what is being used and whether this is matching what is used
on the phone.

[Flo.Matalis]

Hi Mohammed,

This is what I am seeing but still not working.

ROUTER#show call active voice | i Dtmf
tx_DtmfRelay=out-of-band

ROUTER1#show run | i dtmf
mgcp dtmf-relay voip codec all mode out-of-band

[Sreekanth Narayanan]

Can you take these debugs for a test call?
debug mgcp packet
debug isdn q931
debug voip ccapi inout
Please also collect the CUCM traces and provide the SDL file for the same call and provide us the calling and called number details.

[Mohammed al Baqari]

Try to change the dtmf config on mgcp gateway to rtp nte and enable its
mgcp package (dtmf package)

[ROBERT SCHUKNECHT · Accepted solution]

Hi,

some time ago we faced the same problem (after a cucm upgrade to 11.5(1)SU4).

we had to change our mgcp config on the gateway:

remove the follwing commands:

no mgcp rtp payload-type g726r16 static

no mgcp dtmf-relay voip codec all mode out-of-band

add the followong commands:

mgcp package-capability dtmf-package

mgcp rtp payload-type nte 101

mgcp dtmf-relay voip codec all mode nse

maybe it will help.

/Robert

[Flo.Matalis]

Hi Robert! You solution worked! Thanks for your help!
Could this be a bug or an enhancement on 11.5 SU4? We faced the same issue.

[ROBERT SCHUKNECHT]

Hi Flo,

we had a TAC Case open. But i can ot remember if it was a bug or not. Personally for me it is a Bug.

/Robert

[d16lee-TD]

THANK YOU!!!! I literally would pay you real money for this.

[bmuralidharan]

Another beneficiary of this tip!

Thanks for this,

Baktha