Internet - Draft STUN March 2007

Session Traversal Utilities for NAT (STUN) is a lightweight protocol that serves as a tool for application protocols in dealing with NAT traversal. It allows a client to determine the IP address and port Rosenberg, et al. Expires September 6, 2007 [Page 1] Internet-Draft STUN March 2007 allocated to them by a NAT and to keep NAT bindings open. It can also serve as a check for connectivity between a client and a server in the presence of NAT, and for the client to detect failure of the server. STUN works with many existing NATs, and does not require any special behavior from them. As a result, it allows a wide variety of applications to work through existing NAT infrastructure.