Hello,
The first thing I recommend is that you make sure you are using the latest version of Fortress SSH Server. You can get the latest version at
www.pragmasys.com/ssh-server/download.You can increase speed by increasing the window size for file transfers. This can be increased on the client side or the server side.
On the server side, the window size must be set in the registry. Go to HKEY_LOCAL_MACHINE\SOFTWARE\PragmaSystems\SSHD. Increase the value for SSH_Window_size.
Keep in mind that the smallest window size will be used, so even increasing the value for the server might not increase the speed if the client is using a smaller window size.