STUN server
The STUN server allows clients to find out their public address, the type of NAT they are behind and the Internet side port associated by the NAT with a particular local port.
https://www.3cx.com/pbx/what-is-a-stun-server/
The STUN server allows clients to find out their public address, the type of NAT they are behind and the Internet side port associated by the NAT with a particular local port.
https://www.3cx.com/pbx/what-is-a-stun-server/