STUN

STUN is the acronym for Simple Traversal of UDP (User Datagram Protocol) via Network Address Translation (NAT).

The STUN is useful protocol which supports the devices working behind a NAT firewall or a router. STUN also allows applications to discover types and presence of NATs and firewalls between them and the public Internet. It also provides the applications an ability to assess the public IP (Internet Protocol) addresses allocated to them by NAT.

STUNs allows for a wide variety of applications to work via the existing NAT infrastructure.