From owner-freebsd-net Wed Jul 11 16: 6:12 2001 Delivered-To: freebsd-net@freebsd.org Received: from herbelot.dyndns.org (d020.dhcp212-198-27.noos.fr [212.198.27.20]) by hub.freebsd.org (Postfix) with ESMTP id A871D37B401 for ; Wed, 11 Jul 2001 16:06:06 -0700 (PDT) (envelope-from thierry@herbelot.com) Received: from herbelot.com (multi.herbelot.nom [192.168.1.2]) by herbelot.dyndns.org (8.9.3/8.9.3) with ESMTP id BAA20993; Thu, 12 Jul 2001 01:06:43 +0200 (CEST) (envelope-from thierry@herbelot.com) Message-ID: <3B4CDB68.8D06CA81@herbelot.com> Date: Thu, 12 Jul 2001 01:04:08 +0200 From: Thierry Herbelot X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.2.12 i386) X-Accept-Language: en MIME-Version: 1.0 To: Martin Karsten Cc: freebsd-net@FreeBSD.ORG, oscar@ac.upc.es Subject: Re: UDP packet loss on FreeBSD 4.x References: <200107111512.RAA30280@KOM.tu-darmstadt.de> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Hello, FWIW, I've recently built a test bench where I used P-III-450 PCs running 4-port dc(4) NIC (DLINK DFE-570-TX). The tests I've done have shown it's posible with the 4.2-R stock sources (and a tailored kernel) to send AND simultaneously send more than 20k packets/sec with a Packet Loss Rate of less than 1e-5 (when the ports are configured for 100Mbps - full duplex ; the max "correct" throughput for 10Mbps-FD is more like 8 to 10Kpacket/s, still sending and receiving simultaneously) the tests have been done with smallish packets (64 bytes/packet) and 1, 2, 3, 4, and 12 ports per machine (in each case, a total of 20 Kpack/s could be processed that is around 1800packet/s for 12 simultaneous live ports) the packets sent were UDP or raw IP streams (I did not use the xl(4) driver) TfH Martin Karsten wrote: > > Greetings, > > I have observed the following behaviour on FreeBSD 4.x platforms (4.0 till > 4.3 seem to be affected). > > When receiving a sufficiently fast stream of UDP packets (the borderline > seems to be around 3,500 packets/sec for e.g. the 'xl' driver on a 450MHz > Pentium), an application on the receiving host does not receive all packets > anymore, depending on which nic driver is used. A fraction of the lost > packets is reported in net.inet.ip.intr_queue_drops, but not all. > > Tests have shown that the losses occur for the 'xl' or 'ti' drivers, whereas > the 'fxp' and 'de' driver don't seem to be affected. > > On FreeBSD 3.4, no such losses happened and one could easily transmit more > than 10,000 packets/sec between adjacent machines. > > Is this a knowm problem and is there a chance that it is fixed? Is there > potentially a quick solution for it? > > Further, might this problem be related to an earlier report (08 Jan 2001) > sent with the subject "On the performance of the xl driver" by Oscar-Ivan > Lepe-Aldama? > > Thanks in advance, > Martin > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-net" in the body of the message -- Thierry Herbelot To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message