SRB2web-udp-relay

This acts as a UDP proxy layer for SRB2 web using actual SRB2 netgames, you can't host on this relay server.
View the SRB2web source code here.

This ISN'T made to host netgames on, only used to connect to SRB2 UDP servers.
If you're looking to use a server that can be used to host LAN games without forwarding, click here.