STUN Server - Definition, Server and Explanation

STUN, or Session Traversal Utilities for NAT, is a protocol used primarily for NAT traversal. Its main function is to allow devices operating behind a NAT to determine their public IP address and the type of NAT they are using. This is achieved by enabling the device to send a request to an external STUN server, which then responds with details about the public IP address and port from which the request was received. This information is crucial for setting up peer-to-peer communication channels, particularly in applications involving voice and video calls where direct end-to-end data transfer is essential. STUN plays a vital role in various real-time communication protocols, including WebRTC, by assisting in the discovery of Network Endpoint Translation (NET) public addresses.