Jitsi-Videobridge can run behind a NAT, provided that all required ports are routed (forwarded) to the machine that it runs on. By default these ports are (TCP/443 or TCP/4443 and UDP 10000).
The following extra lines need to be added the file `/etc/jitsi/videobridge/sip-communicator.properties`
The following extra lines need to be added the file `~/.sip-communicator/sip-communicator.properties` (in the home directory of the user running the videobridge):