That's rather a question for your hosting provider.
I am using winscp with server4you file serve. its working fine with my previous vds server. then i upgraded my server after that winscp not connecting to server. WinSCp connected to my new server when its not live means no user downloading any file. But when i make it live for users to download file after that winscp not connecting. After that i disconnect it for users then its again connecting to winscp. it means when ever i make my server live for users after that its not connecting to winscp. please tell me the solution of this problem.