The number of simultaneous transfers is under control of the server. When you send PASV, it will respond with none, one or more lines indicating a data port on which it is listening. If you can't work it out from reading manuals (RFC959 is a good start), find a real server that works, and get Wireshark on the job to see what messages go back and forth. (A good server like Filezilla maintains a log so you probably don't need Wireshark, but it'll be useful when you come to debugging your own code.) Peter
Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012