From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: Re: Re: limited network bandwidth with 3.2.x kernels
Date: Thu, 16 Feb 2012 22:59:33 +0100
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Cc: Neal Cardwell <ncardwell@google.com>, netdev@vger.kernel.org
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Le jeudi 16 f=C3=A9vrier 2012 =C3=A0 23:49 +0200, alekcejk@googlemail.c=
om a
=C3=A9crit :
> =D0=92 =D1=81=D0=BE=D0=BE=D0=B1=D1=89=D0=B5=D0=BD=D0=B8=D0=B8 =D0=BE=D1=
=82 =D0=A7=D0=B5=D1=82=D0=B2=D0=B5=D1=80=D0=B3 16 =D1=84=D0=B5=D0=B2=D1=
=80=D0=B0=D0=BB=D1=8F 2012 13:19:58 =D0=B2=D1=8B =D0=BD=D0=B0=D0=BF=D0=B8=
=D1=81=D0=B0=D0=BB=D0=B8:
> > On Thu, Feb 16, 2012 at 12:54 PM,  <alekcejk@googlemail.com> wrote:
> > I still think it would be useful to have these three pieces of data
> > for a slow/3.2.x transfer (from a geographically distant server) if
> > you have a sec:
> >=20
> > - tcpdump of first 300 or so packets to see SYN/SYNACK options and =
RTT
>=20

> > - summary of overall throughput wget sees on that transfer
>=20
> --2012-02-16 23:33:30--  http://speedtest.tele2.net/1GB.zip
> 100%[=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D>] 1 073 741 824 5,02M/s   in 3m 29s
> 2012-02-16 23:36:59 (4,90 MB/s) - =C2=AB/dev/null=C2=BB saved [107374=
1824/1073741824]
>=20
> > This should help establish whether the receiver window is really th=
e
> > limiting factor in the slow cases.
> >=20

Is tweaking /proc/sys/net/ipv4/tcp_adv_win_scale changes the numbers ?

try 1, -1 or -2