Few things : how big are these 200 files ? What is the server timeout ? As blowtorch suggested, in his version the default time out is 15 minutes, in my version of ftpd the default is 2 hours. Check the server timeout on the remote side, if you can. Also, turn on the -v -d flags for verbose and debug, eventually later look at the error codes. What are the operating systems involved, which clients and servers are used ?