FTP Proxy support in FTPSBlackbox - SecureBlackbox®
In addition to SOCKS and HTTP CONNECT (web tunneling) proxies supported in all transport classes FTPSBlackbox client classes support connection via FTP proxy servers.
FTP protocol is different from other protocols in that it uses two socket connections - command and data channel, and information about data channel parameters is passed over command channel. Due to this specifics FTP proxy mechanisms and servers were developed and FTPSBlackbox supports them.
Download SecureBlackbox which includes FTPSBlackbox package.