Fz FTP test - huge packet size shown

Hi,

I've done a FTP test using Filezilla Server running on a Win 7 PC connected to the network with a FastEthernet (100 Mbps) interface. On the PC itself Wireshark was running to capture the ingoing/outgoing traffic

An FTP client does a request to the Fz server (using dst port 21) and then the server (as expected) sets up a TCP connection towards the client using src port 20 (ftp-data).

Now the captured FTP trace shows data packets sent by Fz Server with size up to 11680 byte !!

The very first TCP segments (three-way handshaking for ftp-data connection) have TCP option for MSS and Windows Size scaling...MSS is set to 1460 (byte)

Now, how is it possible to have that huge packet size

Thanks in advance