Hello, I have installed the 3CX phone system on a virtual machine. I have 2 Network cards. One local(for IP phone registration) and one global for VoIP provider registration. In order to register to my VoIP provider i set the field "Which IP to use in 'Contact' and 'Connection' SIP fields" in advanced settings to voip provider menu with my public IP. It registers ok but incoming calls hangs out after 31sec. I use wireshark and i see that all messages (register, ringing etc) have the public IP in contant field in SIP header. The only exception is message 200 OK where the contact field takes the local IP. I use the 3CX version 12.5. Is it a bug? If i change the IP from settings->network and set as external my public IP it works ok, but then i have problems with phone registration. Is there any solution here? Thanks in advance.