As Valentin pointed out in his post, the RadUpload supports only Http and Https as it works exclusively with an ASP handler that processes the files. Currently, the RadUpload does not have functionality to work in FTP environment.
the Telerik team
Registration for Q1 2011 What’s New Webinar Week is now open. Mark your calendar for the week starting March 21st and book your seat
for a walk through all the exciting stuff we ship with the new release!