Hi all, Just a quick note to say that the Snom M3 works extremely well with 3CX. Performance is very good, and it has just the right range of features to make it a useful addition to the Snom range of phones. I have, however, just spent a few hours battling with the lack of inbound audio from behind the firewall. It was only when I checked the NAT Provisioning setting and found it set to "manual" that this solved things and brought back the audio. Since this can be configured from the handset it would be useful to remember to put a pin code into the handset so that prying hands can't fiddle. Other than that, i'm very happy with the phone. Cheers, Mike.