79xx Series DTMF problem when placing outbound call

[Fikri FIRAT]

Hi all,

We have an issue with DTMF signalling on 79xx phones when placing outbound calls through a SIP trunk, can you guide me through fixing it?

Edit : Resetting the trunk resolves the issue but the problem keeps on occuring, we couldn't find any clues why, at least not yet.

Tried changing the configuration of the 'dtmf-relay', didn't work

Tried ' RFC2833 and OOB ' setting on trunk configuration, didn't work

Upgrading firmware, didn't work

Require DTMF reception option at phone configuration was also tested, didn't work either..

on the device , Require DTMF Reception : Enabled

on the trunk , DTMF Signaling Method : RFC 2833

CUCM version : 8.6.2.21007-1

Used firmware : SCCP41.9-2-1S

Regards,

Fikri

[Chris Deren]

Upgrade phone firmware to at least 9.2.3 as there are known DTMF issues with 9.2.1.

HTH,

Chris

[Fikri FIRAT]

Thanks Chris,

Before upgrading the firmware, we tried setting the DTMS Signaling Method to 'OOB and RFC 2833' and then resetting trunk, and it resolved the issue. If the problem occurs again, we will upgrade the firmware on all phones in our networks.

Regards,

Fikri