I have a small problem in that we have a video conference unit going through our firewall but as the call is being made to connect the Sony PCS1 conference unit sees the call but can't answer. I have opened 'ANY' port traffic and using Wireshark can see it asking for 1720. However it cannot complete the connection.
Could this be to do with the 'Application' element of the firewall?
If we connect the video conference unit directly to the internet it works fine. Only using port 1720...