Hi, I installed 3cx pbx on a win2k adv server. I added a extension 100 Now I signed up at freenumber.nl for a voip-in number, and i connected that to a username and sip server. in my case i would say 100=username and sip server = my public ip where my 3cx server is installed on. (this machine is on public ip) but when i call my voip-in number, i see this in the server log: 16:40:37.170 Endpoint::findSource [CM010001] Line configuration does not allow identification of the source of this call. Check Advanced Options for Gateways and Providers and match a field to a correct value from the following: Contact IP: '188.8.131.52'; From: '0031454009110'; To: '101'; Rline: '101'; Contact: '0031454009110' But i don't understand this. at the moment i got extension 101 setup (also a softphone connect to 101 and registered) i got no lines installed, cuz i only want to accept inbound calls on my voip-in number.. in this case my sip server should be my 3cx server who can help me?