For the Horizon interface (the Horizon control panel), port 5000 must be open to log in. The control panel can be accessed via https://osp.combell.com, which is on port 443. When you click on “Connect” the connection goes to port 5000.
The following ports must be accessible to gain access to the APIs:
8042
9696
8776
8000
8004
9292
8774
8776
8777
5000
725