[From QnA]WIZ107SR lost data

This post came from QnA of WIZnet Homepage

I have problems with lost data, when I try to sent larger blocks of data to serial input of WIZ107SR I lost some data.
I tested it with 1024 bytes and only when I used speed 2400 Bd I got whole data.
When I used speed 9600 Bd, I got only 1019 bytes, when I used 115200 Bd I got only 992 bytes.
I tried to activate Flow control CTS/RTS but it didn’t help - RTS never changed its state. How does flow control work?