The agent installed on the servers does not listen to any ports; instead, it connects to our server port 8080. Your client (browser) connects to two servers: our directory server and the ehorus server, both via port 443.
For eHorus to work, you need an internet connection on the servers with eHorus installed, and which is configured to output at port 8080/tcp. If you need to output via a proxy, this can be configured on the agents.
Please consult the relevant documentation for more information. Please note that the firsts beta versions of eHorus, uses 18080/tcp port to connect to servers, but this port changed in version 1.0.