Session Traversal Utilities for NAT
STUN is how WebRTC discovers the public-facing address for peer-to-peer connections. Every WebRTC deployment needs a STUN server.
What It Defines
STUN lets a client behind NAT discover its public IP address and port. Used by ICE as the mechanism for srflx candidate gathering. Defines the STUN message format and binding request/response.
Canonical (Normative)
The canonical publication point for finalized RFCs. If a protocol is standardized as an RFC, the RFC Editor text is the normative final reference. Published by the IETF, IRTF, IAB, and independent stream.
Related Specs
NAT traversal is why WebRTC calls fail. ICE is how browsers find a working path between peers. Know it when debugging call connectivity failures.
~15-20% of WebRTC calls require TURN relay because both peers are behind symmetric NAT. Without TURN, those calls fail silently.
Video calls (Meet, Zoom web), voice calls, peer-to-peer file transfer, and collaborative tools. The browser API surface for real-time A/V communication.