Problem with Yealink T46G Audio Settings

[Heiko]

Hi i am using a 3CX PBX v15.5

Yealink T46G firmware version 28.81.0.61.
 
I want to auto provisioning the T46G with the following parameter:
 
 
Headset Send Volume (-50~50)
 
Description:
 
It configures the sending volume of the headset.
 
CFG Configuration:
 
voice.headset_send
 
Valid Value:
 
(Integer from -50 to 50)
 
 
Handset Send Volume (-50~50)
 
Description:
 
It configures the sending volume of the handset.
 
CFG Configuration:
 
voice.handset_send
 
Valid Value:
 
(Integer from -50 to 50)
 
 
Handfree Send Volume (-50~50)
 
Description:
 
It configures the sending volume of the speaker.
 
CFG Configuration:
 
voice.handfree_send
 
Valid Value:
 
(Integer from -50 to 50)
 
 
And it dont work. The phones dont take the settings.