Plesk FTP Backup slow upload speed

Hello, I set daily ftp backups directly on my office PC.

I installed filezilla ftp server on my office PC, I set my public ip on plesk ftp backup settings and I opened ports on my netgear router. The backups works well, but the upload speed of the backups is about around 1 Megabyte/second. My office dsl connection is about of 1,7-1,8 Megbytes/second (14 Megabits).

Are there speed limits on the plesk ftp backups?

Thanks,

Carlo