Hi netra,
on 802.3 ethernet, there is CRC-32 calculated by the transmitting node and then again by the receiving node on each frame. If they don't match, the frame is discarded.
on FTP protocol, TCP is used, so the reception of all transmit frames is guaranteed by the TCP protocol.
Therefore, the issue sounds to me like a programming error. Over FTP, the data, that is sent, is also received. So, I guess the data corruption in payload occurs somewhere else. Either on server or client side. Maybe you can use a network protocol analyzer tool, like Wireshark, to capture FTP packets and check if they have expected data payload. If possible, try to minimize your application (disable some modules and tasks, like usb, or graphics etc) and see if it has positive effect.