Disclaimer: I wrote this article on March 2022 while working with Subspace, and the original link is here: https://subspace.com/resources/ice-negotiation . This post in my personal blog is a way to ensure it doesn't get lost. There is nothing service-specific in it, I've made only minor edits and I hope it can be a good technical reference on the topic.
WebRTC is a set of protocols that allow applications, typically running on Web browsers, to exchange media (audio, video, data) with other entities.
WebRTC applications use the ICE negotiation to discovery the best way to communicate with a remote party. I t dynamically finds a pair of candidates (IP address, port and transport, also known as “transport address”) suitable for exchanging media and data.