We have a problem with the combination of SNOM 370 phone with Jabra 2400 headset (cable). We connect the cable correct, latest firmware update but for some reasons we cannot hear the person on the other line (the microphone works). For information: we use the fritbox.
It would be great if someone has an idea where the problem is!
Can it be that you connected the cable to the handset jack instead of headset jack? Maybe you could double check?
If you remove the headset and use the standard handset, do you have correct audio both ways?