We have the phone noted above but can't get it to work with 3CX. It's a normal SIP phone and worked fine with our last SIP provider. Whenever we use it on 3CX, after 15 minutes exactly the call drops. To us it shows it's still active, but it has actually hung up on the other person. Does anyone know if there's a setting or something I need to change to make this work properly or why it would drop after 15 minutes exactly every single time? The other issue is that the user that it is assigned to also is set to ring calls on their mobile plus the 3CX softphone. If someone calls, all 3 phones ring, however if they answer the call on their cell or 3CX softphone the Polycom just keeps ringing for over a minute showing incoming call.