Assembly: edtFTPnetPRO (in edtFTPnetPRO.dll) Version: 220.127.116.11
FTP/FTPS uses a separate TCP connection for each data transfer (i.e. upload, download, or directory listing). TCP ports go into a TIME_WAIT state for a number of seconds after each connection, making it unusable for this period. This means that it is possible to run out of TCP ports when multiple files are transferred in a short period of time.
Periodic sleeping can reduce this problem. When enabled through the MultiTransferSleepEnabled property, the connection will wait for seconds each time MultiTransferCountBeforeSleep files have been transferred via multiple-transfer operations.