Accessing Toronto Public Library's Website with Linux

[Giles Orr]

Recently, Matt Price posted to the Toronto Public Library weblog about
an ongoing problem with TPL's website: it's been very slow with Linux
browsers.  We knew about it but didn't know why.  Matt found us an
answer, I got in touch with him, and now that answer is posted to our
website.  Many thanks to Matt, and to Sacha, who Matt says put him on
the right track.

http://www.torontopubliclibrary.ca/hel_tro_index.jsp#linux

Here's the text:

     -----

Some customers have reported slowness accessing Toronto Public Library
websites on computers running the Linux operating system. The problem
is most likely caused by Linux's use of strict internet routing and
firewall settings. We're working on a fix at TPL, but you can also
solve the problem on your computer. Please only attempt this if you're
familiar with the command line and editing files in /etc/ .

First, test the fix by opening a terminal or command prompt with root
privileges and issue this command:

echo 0 > /proc/sys/net/ipv4/tcp_default_win_scale

This change is only effective until your next reboot. Try visiting
some of TPL's pages. If this fix is successful, make the change
permanent by opening /etc/sysctl.conf and adding this line:

net.ipv4.tcp_default_win_scale = 0

Save the file and exit. The library website should load quickly from now on.

     -----

I suspect there are people on this list who will read this and notice
that one possible cause of this is that TPL's routers are
misconfigured.  I'd like to point out that I'm on the web team, and
have nothing to do with the network gear.  And I'd also like to point
out that heckling won't help.  On the other hand, clear details of
what's wrong and how to fix it could be passed along to the right
people and speed the process of a more general fix.

References:
http://www.linuxnet.ch/index.php/TCP_Window_Scaling
http://lwn.net/Articles/92727/
http://www.ietf.org/rfc/rfc1323.txt

-- 
Giles
http://www.gilesorr.com/
gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org
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