Hysteria uses a custom version of QUIC protocol (RFC 9000 - QUIC: A UDP-Based Multiplexed and Secure Transport):
- a custom congestion control (RFC 9002 - QUIC Loss Detection and Congestion Control)
- tweaked QUIC parameters
- an obfuscation layer
- non-standard transports (e.g. faketcp)
The implementation uses Pluggable Transport Specification v3.0 - Go Transport API