Date: Wed, 12 Jan 2005 21:51:11 -0800 From: Brooks Davis <brooks@one-eyed-alien.net> To: Julian Elischer <julian@elischer.org> Cc: net@freebsd.org Subject: Re: TCP out-of-order packets. Message-ID: <20050113055111.GA11141@odin.ac.hmc.edu> In-Reply-To: <41E5C9D8.4090209@elischer.org> References: <41E5C9D8.4090209@elischer.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--AhhlLboLdkugWU4S Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jan 12, 2005 at 05:07:36PM -0800, Julian Elischer wrote: >=20 > I have a link which is provided by someone else that is 7 x E1s aggregate= d. > At leat it looks that way to me when I get to see it. however I have=20 > only been able to get > 60kB.sec across this, despite having a tcp window size of 131072 bytes.. > After investigation it appears that the link is massively re-orderring=20 > packets. > groups of upto 10 packets may appear in random order. (Maybe more, bu tI= =20 > have seen 10) >=20 > in fact packets are rarely IN order. >=20 > This plays havoc with the tcp sessions. >=20 > I was thinking of writing a hacked up version of NATD that > instead of doing NAT, just did a pre-sort on packets from each session,= =20 > so that the receiver would > see a stream of IN-order packets, with occasional delays. >=20 > firstly, does anyone have any tools to do this already (why build when=20 > you can borrow) > and secondly, does anyone have any experience with this sort of problem? >=20 > I have no control over or access to the link.. all I have is a promise=20 > that they will deliver > 14Mb/Sec. with approc 300mSec. RTT to me but there is no promise about=20 > packet order. >=20 > I just get a 100Mb ethernet cable. Have you tried Andre's TCP reassembly rewrite? He says he saw significant improvements in the face of major reordering. http://www.mail-archive.com/freebsd-net@freebsd.org/msg14064.html -- Brooks --=20 Any statement of the form "X is the one, true Y" is FALSE. PGP fingerprint 655D 519C 26A7 82E7 2529 9BF0 5D8E 8BE9 F238 1AD4 --AhhlLboLdkugWU4S Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQFB5gxPXY6L6fI4GtQRAm4uAKCeE/xte3E5E3iceWBBjvzd5lpp3ACgiEo3 mF9X3uBOdAHXYB/Nd/1xkQ0= =P+o4 -----END PGP SIGNATURE----- --AhhlLboLdkugWU4S--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050113055111.GA11141>