How can I split a single direct ftp download into simultaneous multiple parts?

Question

Is there any way, commonly known or purely theoretical, to have a single link to a single file -- say, a typical download file on your regular browser -- but split the transfer itself into multiple parts from the client side?

Essentially, I want to know if it's possible for a computer to split a single network file transfer into two (or more) so that if the computer has multiple network cards (assuming that ISP isn't causing bottleneck), they can effectively download the file at twice the rate. Assume that the download source isn't doing anything to monitor this probably-angering behavior.

Answer 1

FTP supports this via the REST command: http://www.ipswitch.com/support/ws_ftp-server/guide/v5/a_ftpref3.html#10694

Clients usually do feature detection on the FTP server to see if it supports this by issuing the FEAT command.

HTTP also supports this via the Range request header: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35

My favourite client that can do above is aria2: http://aria2.sourceforge.net/