A few of our customers complained about having background noise on the phone during calls. It is not the kind of noise that affects the call in a way that makes it hard to understand the other side, just a consistent background noise when no one is talking on the phone.

I did a few tests in an optimal network setting to eliminate the possibility of packet losses/jitters/delays and tried all the available coders. The background noise is always there, you can't miss it especially if you turn up the volume to max.

I tried with ip112 and ip222 phones, the ip222 are a little better but the noise is still there. Even if you remove the handset completely on the other side you can still hear it.

The only way to get rid of the noise is either to turn off the microphone with the microphone key during the call or to use headsets on both sides (Sennheiser MB Pro 1 in this test case).

Anyone have any ideas on what to do to get rid of this noise? are there any hidden configurations that I can tinker with for the mic and speakers on the telephones?

Aiman