[126097] in North American Network Operators' Group
Re: Edu versus Speakeasy Speedtest
daemon@ATHENA.MIT.EDU (Steve Bertrand)
Fri Apr 30 03:16:16 2010
Date: Fri, 30 Apr 2010 03:15:38 -0400
From: Steve Bertrand <steve@ipv6canada.com>
To: Robert Enger - NANOG <nanog@enger.us>
In-Reply-To: <4BD9FAAD.9050401@enger.us>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 2010.04.29 17:31, Robert Enger - NANOG wrote:
> 1) The capacity that a campus has into I2 or NLR is different than the
> BW the campus purchases from their commercial provider(s).
> 2) The commercial BW test sites are not optimized for speed. They do
> not have unlimited capacity network connections. And, they have not
> tuned their network stack for HS operation: notably, their OS will
> impose memory limits on the socket / transmit-buffer pool; so even if a
> receiver advertises a big window, frequently the transmitter (speed test
> server) will never queue enough data to fill the pipe
> 3) Peering capacity is not what it should be into the networks used by
> some of the BW test sites.
Your observation is disturbingly bleak... do you have a recommendation?
...perhaps a site with good bandwidth and a cluster of iperf(1) boxes
available? :)
Steve
