I wanted to post this message because I just spent approximately 5 hours trying to get FOP2 installed with FreePBX over SSH. There are plenty of documents indicating FOP2 listens on port 4445 by default. The problem is there is very little discussion as to WHY it is listening on port 4445.
TCP/4445 is used by the Flash client to communicate with the Flash Operator Panel on the server. If you are installing FOP2 via port forwarding TCP/80 over SSH then your client cannot access the server unless you also forward port 4445.
ssh root@<serverip> -L 4445/localhost/4445
If you fail to forward those ports then you will be presented with the login screen, you can enter your credentials but after that you will only see..
"Connecting to server, attempt number 1" .... "Connecting to server, attempt number 9"... FAILED.
Of course I have over 25 years of IT experience so I should have known better but I completely spaced it. Hopefully this will remind the next guy.