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Date:      Mon, 21 Jul 2014 11:27:36 +0800
From:      Niu Zhixiong <kaiaixi@gmail.com>
To:        bycn82 <bycn82@gmail.com>
Cc:        freebsd-net@freebsd.org
Subject:   Re: A TCP problem on High Delay
Message-ID:  <CAOENNMAB=1tZXKKRXvQ_NjHe8yv-NXh_yOrjwNp8r6gpPMg8Kg@mail.gmail.com>
In-Reply-To: <00d201cfa436$d2936ce0$77ba46a0$@gmail.com>
References:  <CAOENNMCvrD91SiMfyySB1Qj7Ysvhcv1r2t-WGQV=Qb7CKe8DUA@mail.gmail.com> <00d201cfa436$d2936ce0$77ba46a0$@gmail.com>

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Hi,
Thank you so much. I am wondering that why FreeBSD default is less than
Linux default in high delay * BW. Why, Why and Why.

@FreeBSD_KVM:~ % sysctl net.inet.tcp
net.inet.tcp.rfc1323: 1
net.inet.tcp.mssdflt: 536
net.inet.tcp.keepidle: 7200000
net.inet.tcp.keepintvl: 75000
net.inet.tcp.sendspace: 32768
net.inet.tcp.recvspace: 65536
net.inet.tcp.keepinit: 75000
net.inet.tcp.delacktime: 100
net.inet.tcp.v6mssdflt: 1220
net.inet.tcp.cc.algorithm: newreno
net.inet.tcp.cc.available: newreno
net.inet.tcp.hostcache.cachelimit: 15360
net.inet.tcp.hostcache.hashsize: 512
net.inet.tcp.hostcache.bucketlimit: 30
net.inet.tcp.hostcache.count: 0
net.inet.tcp.hostcache.expire: 1
net.inet.tcp.hostcache.prune: 300
net.inet.tcp.hostcache.purge: 0
net.inet.tcp.log_in_vain: 0
net.inet.tcp.blackhole: 0
net.inet.tcp.delayed_ack: 1
net.inet.tcp.drop_synfin: 0
net.inet.tcp.rfc3042: 1
net.inet.tcp.rfc3390: 1
net.inet.tcp.experimental.initcwnd10: 1
net.inet.tcp.rfc3465: 1
net.inet.tcp.abc_l_var: 2
net.inet.tcp.ecn.enable: 0
net.inet.tcp.ecn.maxretries: 1
net.inet.tcp.insecure_rst: 0
net.inet.tcp.recvbuf_auto: 1
net.inet.tcp.recvbuf_inc: 524288
net.inet.tcp.recvbuf_max: 16777216
net.inet.tcp.path_mtu_discovery: 1
net.inet.tcp.tso: 1
net.inet.tcp.sendbuf_auto: 1
net.inet.tcp.sendbuf_inc: 16384
net.inet.tcp.sendbuf_max: 16777216
net.inet.tcp.reass.maxsegments: 7900
net.inet.tcp.reass.cursegments: 0
net.inet.tcp.reass.overflows: 0
net.inet.tcp.sack.enable: 1
net.inet.tcp.sack.maxholes: 128
net.inet.tcp.sack.globalmaxholes: 65536
net.inet.tcp.sack.globalholes: 0
net.inet.tcp.minmss: 216
net.inet.tcp.log_debug: 0
net.inet.tcp.tcbhashsize: 16384
net.inet.tcp.do_tcpdrain: 1
net.inet.tcp.pcbcount: 4
net.inet.tcp.icmp_may_rst: 1
net.inet.tcp.isn_reseed_interval: 0
net.inet.tcp.soreceive_stream: 0
net.inet.tcp.syncookies: 1
net.inet.tcp.syncookies_only: 0
net.inet.tcp.syncache.bucketlimit: 30
net.inet.tcp.syncache.cachelimit: 15375
net.inet.tcp.syncache.count: 0
net.inet.tcp.syncache.hashsize: 512
net.inet.tcp.syncache.rexmtlimit: 3
net.inet.tcp.syncache.rst_on_sock_fail: 1
net.inet.tcp.msl: 30000
net.inet.tcp.rexmit_min: 30
net.inet.tcp.rexmit_slop: 200
net.inet.tcp.always_keepalive: 1
net.inet.tcp.fast_finwait2_recycle: 0
net.inet.tcp.finwait2_timeout: 60000
net.inet.tcp.keepcnt: 8
net.inet.tcp.rexmit_drop_options: 0
net.inet.tcp.per_cpu_timers: 0
net.inet.tcp.timer_race: 0
net.inet.tcp.maxtcptw: 12963
net.inet.tcp.nolocaltimewait: 0


Regards,
Niu Zhixiong
=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=
=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D=EF=BC=8D
 kaiaixi@gmail.com


On Mon, Jul 21, 2014 at 12:22 AM, bycn82 <bycn82@gmail.com> wrote:

> Hi,
> Yes, according to your pcap files,it is because of the window size.
> more information here http://www.ietf.org/rfc/rfc1323.txt
> and share the result of "sysctl net.inet.tcp"
>
> Regards,
> bycn82
>
>
>
> > -----Original Message-----
> > From: owner-freebsd-net@freebsd.org [mailto:owner-freebsd-
> > net@freebsd.org] On Behalf Of Niu Zhixiong
> > Sent: 20 July, 2014 23:43
> > To: freebsd-net@freebsd.org
> > Subject: A TCP problem on High Delay
> >
> > Dear All,
> >     I set up an FTP server in a high delay but fairly BW environment.
> >     When I try to download files from this FreeBSD FTP server, A FreeBS=
D
> > client is always slower than Linux Client. (Linux Client is about 1MB/s=
,
> > But FreeBSD client 300KB/s). I am sure that the two clients are in same
> > networks and no firewalls are between server and clients. Then I try to
> > use SCTP protocol rather than TCP protocol. The FreeBSD client is faste=
r
> > than itself in TCP.
> >
> > I try to increase the rbuff of the client. But, It always less than the
> > linux one. I think the problem may be the smaller window of Freebsd tha=
n
> > Linux. But, I changed some parameters. But, nothing changed.
> >
> > uname -a
> > 10.0-RELEASE FreeBSD 10.0-RELEASE #0 r260789: Thu Jan 16 22:34:59 UTC
> > 2014
> >     root@snap.freebsd.org:/usr/obj/usr/src/sys/GENERIC  amd64
> >
> > According to
> > http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-
> > kernel-limits.html
> >
> > I try to enable sysctl net.inet.tcp.inflight.enable or sysctl
> > net.inet.tcp.inflight_enable , but there is no such option in FreeBSD 1=
0.
> >
> > Then I follow this https://fasterdata.es.net/host-tuning/freebsd/
> > And make a large rbuffer.
> >
> >
> > sysctl   kern.ipc.maxsockbuf=3D16777216
> > sysctl   net.inet.tcp.sendbuf_max=3D16777216
> > sysctl   net.inet.tcp.recvbuf_max=3D16777216
> > sysctl  net.inet.tcp.sendbuf_auto=3D1
> > sysctl  net.inet.tcp.recvbuf_auto=3D1
> > sysctl   net.inet.tcp.sendbuf_inc=3D16384
> > sysctl   net.inet.tcp.recvbuf_inc=3D524288
> > sysctl   net.inet.tcp.hostcache.expire=3D1
> >
> > But, Nothing is happened.
> >
> > In the attachments, l_f is the linux packet capture and f_f is the
> > freebsd packet capture.
> >
> >
> >
> >
> > =E2=80=8B
> >  packet_capture.7z
> > <https://docs.google.com/file/d/0By8sTL79ob4tTTBYQmhQT2Uxajg/edit?usp=
=3Ddr
> > ive_web>
> > =E2=80=8B
> > _______________________________________________
> > freebsd-net@freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-net
> > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
>
>



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