SOLVED. GXP1625 - Incoming call. Phone is like muted


I don’t know since when I got this problem, as my GXP1625 is located in a room that is not often used. I did not change the config parameters.
The phone rings when the number is called, but I cannot hear the caller, neither he can hear my voice. The phone is like muted, although the mute logo isn’t displayed.
When I press the line key for line 2 and afterwards the key for line 1 , the phone state changes to unmuted without any changes on the LED display.

Can anyone tell me what needs changed, please?

Best regards


Haven’t plugged the handpiece into the headset port?


As I wrote in my text:

May be that this was misleading or uncomplete: after I pressed the line key 2 and than the line key 1 I was able to pick up the call. I have no Problems at all with outgoing calls. As I mentioned: I did not Change the config.


It can be microphone function.

Check what you have set.


Many thanks for the hint, but this function is set with “DND” activated.
Strangely, the problem is solved due to one of the last few nightly updates.
Thank you anyway for your hints


I have the same exact problem on my GXP2140 I can make calls but when I answer a call, both incoming and outgoing audio is dead unless I select another line (puts answered line on hold) then select back and then the audio is working.

Running latest firmware

I have also reset the phone to factory and set up again from scratch.

Any suggestions?


Must be codec problem or connection.
Hold and resume sent new SDP. Without packets i cannot say anything more.


Thanks @Marcin You are correct.
further analysis, firewall syslog and p-cap from the phone was submitted to GS support and they diagnosed a codec problem and this was fixed by taking their advice to change the Account x, audio settings Codec Negotiation Priority to Caller( )
The factory setting is Callee.

Posting the results to help others.