[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Bug-wget] Support for long-haul high-bandwidth links

From: Andrew Daviel
Subject: Re: [Bug-wget] Support for long-haul high-bandwidth links
Date: Tue, 29 Nov 2011 13:23:35 -0800 (PST)

On Sat, 26 Nov 2011, Ángel González wrote:

On 10/11/11 03:24, Andrew Daviel wrote:

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

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 server, and achieve a significant speedup.

I wondered it this was of interest as an enhanscement for wget.

I think setting a big SO_RCVBUF should also fix your issue, by using big
window sizes, and it's cleaner.
OTOH, you need support from the TCP stack, and that won't trick
per-connection rate limits that may be
limiting you in the single-connection case.

Yes, jumbo frames work well over a private link like a lightpath. I'd been thinking of something that would work on the unimproved public internet.

I had been thinking of speeding up transfers to e.g. a WebDAV repository on another continent, but I became recently aware of "download accelerators" designed primarily to thwart bandwidth allocation/throttling. Interestingly Wget is listed on the Wikipedia page as a "download manager", implying it can already do this.


Andrew Daviel, TRIUMF, Canada

reply via email to

[Prev in Thread] Current Thread [Next in Thread]