STUN is a toolset for NAT traversal in IP networks. Originally it was intended for usage with UDP datagrams, but has later been extended to work with other transports, as well. STUN Client Test Suite can be used for evaluating STUN client implementations for security flaws and robustness problems.
STUN - Simple Traversal of User Datagram Protocol (UDP)Through Network Address Translators (NATs)
Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer Protocols
Session Traversal Utilities for NAT (STUN)
Managing Client Initiated Connections in the Session Initiation Protocol (SIP)
Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN)
NAT Behavior Discovery Using STUN
Test vectors for STUN
Traversal Using Relays around NAT (TURN) Extensions for TCP Allocations
Traversal Using Relays around NAT (TURN) Extension for IPv4/IPv6 Transition
Explicit Congestion Notification (ECN) for RTP over UDP