When MinDataPort property is set to value different than 0, it
defines lowest port number to be used for data connections in FTP
and FTPS protocols (this property is ignored in SFTP protocol). It
is used when client sends PASV command, and server needs to open
second, data connection, to transfer file or directory listing.
This property is used when your server is behind a firewall and
only certain range of ports is accessible through the firewall.
Usually, these are values a bit above 1024, although any range
between 1024-65535 can be used.
If you don't set this value, or is set to 0, wodFTPServer will
not use any specific range, and will always use whatever port
windows assigns.