You are saying that you have
udp 14,7/14,7 Mbps
tcp 2,2/8,2 Mbps
and only in ftp transfer you get 8kb ?
Should your ftp server shape your connections in any way ? Is there a restriction on it ?
Try to transfer files with filezilla. See what happens. I got some weird results testing against a ftp server far away, and with filezilla i was getting at least double the speed of other programs.
Do try that. Or, try on another ftp server. Or, you could put a user with only ftp rights on one of your rb ( say rb333 cause you have more space), and transfer a 10 mb file from/to there.
See what you get.