Red Hat Bugzilla – Bug 130496
Poor TCP performance with usbnet driver
Last modified: 2007-11-30 17:10:47 EST
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User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7)
Description of problem:
Upgrading my FC2 kernel from 2.6.5-1.358 to 2.6.8-1.521 has caused
poor performance on TCP when browsing certain websites (using Firefox)
with my cable modem (Ambit). I'm not sure when the problem appeared
because 2.6.5-1.358 was the last kernel where my ethernet (nvidia)
worked until now. An ethereal capture shows the TCP window for the
working case increasing but not for the non-working case.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Go to http://www.ebay.co.uk and get a page with "a lot" on it. In
my case, it's my standard eBay page but a search page should have the
same symptoms. In may case, I'm using Firefox (will try others later).
Actual Results: Expect webpage to load promptly.
Expected Results: Web page is extremely slow to load.
Created attachment 102937 [details]
Extract of ethereal capture for working case
Created attachment 102938 [details]
Extract of ethereal capture for non-working case
Try: echo "0" >/proc/sys/net/ipv4/tcp_default_win_scale
If that fixes it, the problem is in either a router or
firewall between your host and the remote web site.
It is not a bug in Linux.
That does the job. Cheers.