Additionally red5 uses some ports internally. However those ports are not in use by OpenMeetings by default.
You need to change two files:
Every server side configuration has a client side representative
|Config-Name||Default-value||Name in red5.properties||Name in public/config.xml|
A common way of bypassing the firewall is to change HTTP port to 80 and rtmpT to 443.
A short description about the connection mechanism: The application first tries connecting to rtmp 3 times, because rtmp is the protocol that is less performance hungry. If that fails the application will fallback to rtmpT.
Most firewalls do allow traffic on port 443 and they normally do not analyse the packets, because 443 is normally SSL encrypted, so the firewall should not be able to read the packets at all.
You can run OpenMeetings completely over SSL. See RTMPSAndHTTPS .