56k modem upload/download speeds

A nice easy one to answer, i have a 56k modem, do the upload speeds and download speeds run unaffected by each other, as someone once told me that the more i download the slower the uploading goes and i had no need to disbelieve that, but recently using file sharing networks my download speeds seem unaffected by uploading at the same time.

So is the download speed independant of the upload speed on a 56k modem, aka i download at 4.5k/s max and upload at 2.5k/s max, can i do both of these at once

Killerkris

A Life, where can i download one of those from?