From: Carsten Wolff <carsten@wolffcarsten.de>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Yuchung Cheng <ycheng@google.com>,
"Esztermann, Ansgar" <Ansgar.Esztermann@mpi-bpc.mpg.de>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: TCP fast retransmit
Date: Thu, 15 Dec 2011 08:41:06 +0100 [thread overview]
Message-ID: <201112150841.08087.carsten@wolffcarsten.de> (raw)
In-Reply-To: <1323901909.2631.17.camel@edumazet-laptop>
On Wednesday 14 December 2011, Eric Dumazet wrote:
> Le mercredi 14 décembre 2011 à 11:00 -0800, Yuchung Cheng a écrit :
> > I use tcptrace to check the time sequence and I am puzzled:
> > I see a lot of OOO packets too but how can this happen at a sender-side
> > trace? unless the trace is taken close to but not exactly at the sender.
> > I expect on seeing in-sequence packets but a lots of SACKs plus some
> > spurious retransmists.
>
> I understood the trace was a receiver-side one (a linux machine if I am
> not mistaken, while the sender is AIX powered)
>
> (Looking at timings of ACKS, coming a few us after corresponding data
> packet arrival)
Oh. Right. This also means, that net.ipv4.tcp_reordering is only available at
the receiver (Linux), which doesn't help, because the reordering robustness
stuff happens on sender-side. So don't even bother changing that sysctl.
Carsten
next prev parent reply other threads:[~2011-12-15 7:41 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-25 13:33 TCP fast retransmit Esztermann, Ansgar
2011-11-25 16:36 ` Eric Dumazet
2011-11-25 16:39 ` Eric Dumazet
2011-11-29 9:00 ` Esztermann, Ansgar
2011-12-09 13:34 ` Esztermann, Ansgar
2011-12-09 14:43 ` Eric Dumazet
2011-12-09 16:17 ` Esztermann, Ansgar
2011-12-09 16:31 ` Eric Dumazet
2011-12-13 14:05 ` Esztermann, Ansgar
2011-12-13 14:31 ` Eric Dumazet
2011-12-13 14:59 ` Carsten Wolff
2011-12-14 19:00 ` Yuchung Cheng
2011-12-14 22:31 ` Eric Dumazet
2011-12-15 7:41 ` Carsten Wolff [this message]
2011-12-15 8:24 ` Eric Dumazet
2011-12-16 15:53 ` Esztermann, Ansgar
2011-11-25 16:57 ` Ilpo Järvinen
2011-11-28 21:17 ` Yuchung Cheng
2011-11-29 9:00 ` Esztermann, Ansgar
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