http://i3xi5qxvbrngh3g6o7czwjfxwjzigook7zxzjmgwg5b7xnjcn5hzciad.onion/proposals/348-udp-app-support.html
These applications are currently niche but we expect they may rise in popularity. WebRTC WebRTC is a large collection of protocols tuned to work together for media transport and NAT traversal.
It is increasingly common, both for browser-based telephony and for peer-to-peer data transfer.