SSH Tunnels and Xymon

Hi Guys

We just setup a SSH tunnel link between our Main Hobbit server and several external sites. I just wanted to check with you wizards out there about which ports I need for full Xymon monitoring. From what I understand port 1984 has to be open? The connection test is my main concern which ports needs to be open for Xymon to run a connection test?

Regards

Neil