[Bloat] the observed sack oddity

[Eric Dumazet]

Le mardi 11 octobre 2011 à 15:11 +0200, David Täht a écrit :
> Of course, it would help if I posted a link to the screenshots!
> 
> http://www.teklibre.com/~d/sackoddity/
> 
> On 10/11/2011 03:09 PM, David Täht wrote:
> > I have put up screenshots of tcptrace -G and xplot.org's analysis of my
> > most recent capture of an ipv6 connection over freebox (wired) from a
> > debloat-testing kernel here in france (pre 3.1 by a lot) to a 2.6.16
> > kernel (the aformentioned netsonar box) in redwood city, ca, both
> > running tcp cubic, over ipv6.
> >
> > at first glance, it looked a lot like a classic bufferbloat trace, with
> > complete with periodic collapses and cubic increasing the window.
> >
> > Then I noticed the sacks.
> >
> > I also have a trace taken between the debloat-testing box and a cerowrt
> > box (running linux 3.04), both running westwood, which shows
> > considerably less undesirable behavior, and I will repeat that test with
> > cubic this evening and post additional data tomorrow morning.


Who is the sender ?

Is some WIFI involved ?

"netstat -s" on the receiver would help

This might be a truesize mismatch.