7937 not passing DTMF through sip trunk

Unanswered Question
Feb 4th, 2008

Hi there,

Quick question, we just got a 7937 conference phone. When we dial a specific number we have the call go through a Sip trunk to a sip device. When the call connects, the call does not pass dtmf to the connected device.

All the other phones in our network seem to pass dtmf over this trunk properly, except the new phone. I have updated the phone to version 1.1 of the firmware

I am also runnning CM 5.1.1

I have this problem too.
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connect101 Wed, 02/06/2008 - 20:52

I have the same problem but with a 7971G.

I'm running CM5.1.3


jbarcena Fri, 05/23/2008 - 12:50

What type of DTMF do you have in the dial-peer that is handling the call?

lafirzaman Fri, 10/03/2008 - 02:11

There is a known defect about it in 1.0(2). This defect is fixed in

1.2(1) like "CSCsm04556 - 7937 sends wrong DTMF digits when pressing * and #" and "CSCso31642 - 7937 IP phone does not transmit RFC 2833 on a sip trunk with 5.X CUCM".

You can double check the firmware file from the callmanager interface : Device > Device Settings > Device Defaults, look for the 7937, and if 1.0(1), you should see "apps37sccp.1-0-1-0" in front of the 7937 (that is the standard version with 6.1.1 or earlier).

so probably you need an upgrade.


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