ICE
Interactive Connectivity Establishment
ICE is a NAT Traversal mechanism which incorporates both the STUN and TURN protocols. Developed by the IETF MMUSIC working group, ICE is deployed in many next generation networks to allow VoIP users positioned behind a NAT device to send signalling to other VOIP users. Crucially, this signalling contains addressing information which is useable, due to the fact that prior to sending the signalling, the VoIP client will have interrogated an ICE server to ascertain the addressing information required for the eventual media streams.