WebSocket inbounds will parse the `X-Forwarded-For` header received, overriding the source address with a higher priority than the source address got from PROXY protocol.
The [PROXY protocol](https://www.haproxy.org/download/2.2/doc/proxy-protocol.txt) is used to transmit the real source IP and port of connections. **If you are not familiar with this, leave it alone.**
Commonplace reverse proxy software solutions (like HAProxy and NGINX) can be configured to have source IPs and ports sent with PROXY protocol. Same goes to VLESS fallbacks `xver`.
When `true`, after the underlying TCP connection is established, the downstream must first send the source IPs and ports in PROXY protocol v1 or v2, or the connection will be terminated.
If `path` contains the `ed` query parameter, `early data` will be activated for latency reduction, and its value will be the length threshold of the first packet. If the length of the first packet exceeds this value, `early data` won't be activated. The recommended value is 2560, with a maximum of 8192. Compatibility problems can occur when the value is set too high. Try lowering the threshold when encountering such problems.