PhantomVl
commented
6 years ago "Force_dtmf is only required in very strange situations where normal behaviour does not work (for example when combined with Nat and directrtp it is sometimes necessary to force inband dtmf)." If you really need this option then you need to edit the following files: instal.php, sccpgeneral.xml.v431
instal.php -> Line number 156 -> // 'force_dtmfmode' - remove coments sccpgeneral.xml.v431 -> Line number 1101 -> item type="IS-disabled" id="6" seq="99" change to item type="IS" id="6" seq="99"
Unfortunately I can't promise what the current lines numbers to be retained in subsequent updates.
When you setup the phone device, can you add an option to set the DTMF mode since not all phones (especially older versions) do not support rfc2833 (inband) dtmf. I believe the dtmf is normally set in the sccp_hardware.conf but when using SCCP Manager there's no sccp_hardware.conf file anymore.
force_dtmfmode = auto ; auto, skinny or rfc2833. Some phone models with bad firmware do send dtmf in a messed up order and need to be forced to skinny mode.