I don't understand what you are trying to connect to. Is your site located at some remote server?
Normally, people work from their desktop or laptop and to define the site definition, you simply go to:
Site >> New Site
and follow the on screen instructions.
There is no connection involved unless you are also trying to input all the optional ftp details. If so then you will need to contact your host if they can email you the details once again.
Try exporting the site definition again.
Follow the steps for importing the site definition as explained in tech note below.
If that does not help. Try modifying(leave blank or just put a /) your root folder location and the test.