Does jitsi meet connect the jvb port 10000/udp through websocket? if yes
if no then why does port 10000/udp have to be publicly open?
AFAIK, port 10000/udp is used for media traffic.
This is different from the websocket connection which is used for client-to-bridge messaging. See jitsi-videobridge/web-sockets.md at master · jitsi/jitsi-videobridge · GitHub
You don’t have to have websockets enabled, you can disable it from /etc/jitsi/… The connection does not directly go through 10000, there must be a communication of some kind I guess.