TCP and UDP
TCP and UDP are two ways to send data: TCP is reliable and ordered; UDP is fast but does not guarantee delivery.
Think of it like this
TCP is registered mail — signed for and resent if lost. UDP is a postcard — sent and forgotten, but quick.
In this setup
Web pages and AI chats mostly use TCP; video calls, games and the browser's WebRTC use UDP. Both nodes forward UDP. But Clash Verge's "System Proxy" mode only takes over TCP, so to stop WebRTC leaks you need "Tun Mode".
Common misconceptions
- "UDP is insecure": UDP is just a transport; security depends on what runs over it.
Related: WebRTC, System proxy vs TUN