Keepalive (FTPKEEPALIVE)

Keepalive is used to send packets over the control connection to keep a session active. This keeps the firewall from timing out and terminating the connection. Use the keepalive interval to specify the number of seconds that the keepalive mechanism should wait before sending another packet over the connection.

Check the box labeled "Use keepalive" to activate this function and optionally you may modify the interval.