We have static ips with 1:1 Nat and so have a dedicated ip and and static port forwarding on our 3cx server. All works correctly. In the Networking section we have turned off Stun and put in our public ip. In each voip provider we have also turned off stun and put in our public ip. When we register the correct public ip is being sent. But when we send an invite the internal ip is being sent. Sidenote: I believe the registration contact ip is picked up from the voip provider settings but the invite contact ip is picked up from the STUN tab in the Network settings. Can you confirm this is a bug?