When transferring a large file over a high-latency (e.g. long physical
distance) high-bandwidth link, the transfer time is dominated by the round-trip
time for TCP handshakes.

In the past tools such as bbftp have mitigated this effect by using multiple
streams, but required both a special server and client.

Using the "range" header in HTTP/1.1, it is possible to start multiple
simultaneous requests for different portions of a file using a standard Apache
WebDAV server, and achieve a significant speedup for both GET and PUT. I have a
proof-of-principle Perl script using threads which was able to download a
medium-sized file from Europe to Vancouver in half the normal time. I
also tested uploads wit hPUT, but only over a short distance.

I wondered if this was of interest as an enhancement for Curl.

regards

-- 
Andrew Daviel, TRIUMF, Canada
-------------------------------------------------------------------
List admin: http://cool.haxx.se/list/listinfo/curl-library
Etiquette:  http://curl.haxx.se/mail/etiquette.html