Signaling > Stun Turn Ice NATS
A host uses Session Traversal Utilities for NAT (STUN) to discover its public IP address when it is located behind a NAT/Firewall.
When this host wants to receive an incoming connection from another party, it provides this public IP address as a possible location where it can receive a connection.
If the NAT/Firewall still won't allow the two hosts to connect directly, they make a connection to a server implementing Traversal Using Relay around NAT (TURN), which will relay media between the two parties.
Interactive Connectivity Establishment (ICE) is a blanket standard that describes how to coordinate STUN and TURN to make a connection between hosts. Twilio's Network Traversal Service implements STUN and TURN for ICE-compatible clients, such as browsers supporting the WebRTC standard.