The default for Videobridge is 5275, my instincts tell me that Prosody and Videobridge cannot be using the same port. Is that true, and if so, is it good practice to just go ahead and assign port 5275 to Videobridge??
jvb (videobridge) connects to prosody on port 5347 (tcp) and listens on port 10000 (udp). There is no reason to change that.
The message in Debian postinst talking about 5275 is misleading (maybe it’s a relic of a forgotten era)