Date: Thu, 18 Feb 2010 17:04:35 +0100 From: Harald Schmalzbauer <h.schmalzbauer@omnilan.de> To: Stephen Hurd <shurd@sasktel.net> Cc: freebsd-stable@freebsd.org, Patrick Mahan <mahan@mahan.org> Subject: Re: RELENG_8 ignoring TCP window size? [Was: Re: Help for TCP understanding wanted, ACK-MSS-Window [Was: Re: best practice to watch TCP parms of established sockets]] Message-ID: <4B7D6513.6020406@omnilan.de> In-Reply-To: <4B7D645D.3090104@sasktel.net> References: <4B7C1365.9070806@omnilan.de> <70CD649D-7659-4CE2-A16C-49B8C891CB5B@mac.com> <4B7C4066.5040006@omnilan.de> <4B7D3938.1000309@omnilan.de> <4B7D5AC4.9020509@mahan.org> <4B7D61DE.2020906@omnilan.de> <4B7D645D.3090104@sasktel.net>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig24FCC04F34504334AF94C7C0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Stephen Hurd schrieb am 18.02.2010 17:01 (localtime): > Harald Schmalzbauer wrote: >> Some experimental results: >> When rsyncing with windows, and FreeBSD is receiver, I see the same=20 >> ACK ever two segemnts, but speed is at 72MB/s. >> When FreeBSD is sender and Windows is receiver, it looks more I=20 >> expected. There are about 20 data segments before a ACK is returned.=20 >> And there are TCP Window Update Segments, reflecting smaller receiver= =20 >> buffers on the windows side. But this happens at a throughput of=20 >> 82MB/s!!! So the windows machine is behaving like I understand the TCP= =20 >> flow control. >> Any explanation why the FreeBSD machine seems to ignore window size? >=20 > IIRC, the delayed ACK RFC requires an ACK at least every second segment= =2E Good hint, but disabling leads to ACK after every single data segment ?!?= Thanks, -Harry --------------enig24FCC04F34504334AF94C7C0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.13 (FreeBSD) iEYEARECAAYFAkt9ZRQACgkQLDqVQ9VXb8jQtwCfZnCWjfH5hQ92PMd4KgHrZtXZ lzoAnRGFYEg3iwLw7N/PonsMx3hCEXxQ =d8DW -----END PGP SIGNATURE----- --------------enig24FCC04F34504334AF94C7C0--
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