Date: Sat, 04 Jan 2014 11:20:13 -0800 From: Peter Wemm <peter@wemm.org> To: freebsd-net@freebsd.org Cc: Gavin Atkinson <gavin@FreeBSD.org>, andre@freebsd.org, Peter Wemm <peter@freebsd.org> Subject: Re: Long-haul problems - connections stuck in slow start Message-ID: <52C85EED.801@wemm.org> In-Reply-To: <52C85537.7080307@wemm.org> References: <52C85537.7080307@wemm.org>
next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --2qhRgDNowvCSusNohUdo2nMLk15gglXSo Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 1/4/14, 10:38 AM, Peter Wemm wrote: > We're seeing some unfortunate misbehavior with tcp over an intercontine= ntal > link. I forgot to mention, the socket buffers have been generously tuned for th= ese endpoints. They don't seem to be being used while the sender is in some s= ort of limited transmit mode. When reading the tcpdumps, keep in mind the window scaling factor is 11 a= nd that's wasn't captured in the session. You'll have to manually compensat= e when reading the mid-session dumps. XXX footnote: It seems turning SACK off makes a huge difference for this= connection. The server must have been running with sack disabled when it= was working and hadn't been saved in sysctl.conf. Turning sack off on the= server again has raised the throughput from 8K/sec to 32MB/sec. That's a= nice 400x speedup. I'm investigating. --=20 Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com; KI6F= JV UTF-8: for when a ' just won\342\200\231t do. --2qhRgDNowvCSusNohUdo2nMLk15gglXSo Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlLIXu0ACgkQFRKuUnJ3cX8ORgCdGqZX/IMlh5I8TScjlHeXhcNb cFMAmgKr7VehEc8qO78XQngQJLycdyXT =yPlr -----END PGP SIGNATURE----- --2qhRgDNowvCSusNohUdo2nMLk15gglXSo--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?52C85EED.801>