Alexandre, You have a lot of questions here. Let's start with some level setting. Using UDP there may be some packet drops depending on how fast the packets are being processed. I think you may need to set the volume to packets (throughput) you are going to be sending/receiving on you device and see if packets are still being dropped on that device. From what you say below it doesn't look like the 82580 device/system is dropping any packets. It's the other systems/devices with the drops right?
What is happening when you see RNBC (receive no buffer count) is that the packets aren't being processed fast enough by the system and if it continues you see the MPC (missed packet count) increase when the packets are actually dropped. This could be happening due to the a slow system, slow bus, something else on the system taking up CPU or PCI bus bandwidth, etc. So I would recommend testing this again with the your device with the 82580 and one other higher-end system as the link partner. Set the test up for you desired throughput and see what your systems do with that throughput. I wouldn't use you laptop as a partner, use a server type system if possible. Limit what is running on it while you are testing. Disable other PCI/PCIe devices in the system, if possible, if they are taking up lots of bus bandwidth. You also did not say what Linux version you are using on your system. This can also have an effect on what you are seeing. You talk about your HW and Lanconf but not the system SW. Please let us know. BTW, the packet drops you are seeing is not excessive at all but possible can be reduced if the test is correct for your environment. Cheers, John > -----Original Message----- > From: Alexandre Desnoyers [mailto:[email protected]] > Sent: Tuesday, November 01, 2011 5:50 AM > To: [email protected] > Cc: <[email protected]> > Subject: [E1000-devel] Intel GigE NIC - Missing lots of packets > > Hello everyone, > > I've just registered to the mailing list following the recommendation > of Peter Waskiewicz from Intel. > > > Here is the situation: > I've designed an embedded x86 board with a Intel 82580 NIC (both dual > and quad GigE). We're seeing some packet loss when using either "ping > -f", "iperf" and "netperf" under Linux. After investigating a little > more, I found the DOS LANConf tool that can be used to test the NIC > according to IEEE standards. > > Our embedded application is a real-time image analysis system, and the > image frames are sent via UDP packets to another computer > (point-to-point). We're seeing some packet losses and are trying to > debug this. > > Sorry for using Tinypic links for the screenshot... but I believe that > the server do not support attachment. Feel free to request a personal > email with the properly named attachment. > > Questions: > > ----------------------------------------------------------------------- > ----- > > 1) Can you recommend an Intel PCIe NIC "reference" card that can be > used as traffic generator? I was thinking about the "Intel PRO/1000 PT > Server Adapter", but maybe you have a better recommendation. > > Right now, I'm using the LOM 82578DC NIC from an Intel DH55TC > motherboard as the traffic generator for LANConf. > > According to the Intel "1000BASE-T/100BASE-TX/10BASE-T Physical Layer > Compliance Tests Manual", version 4.3, the recommended NIC is a 82543, > but it's now listed as "end of life" on Intel's website... And it only > has a PCI interface which is not fast enough for full speed GigE > testing > (confirmed with an old Intel 82541 based PCI card) > > > What is the architectural differences between the client and server > NICs? I need to convince my boss to spend the money on the correct > card :) > > ----------------------------------------------------------------------- > ----- > > 2) When doing the Send/Receive LANConf test between my 82580 and the > 82578DC LOM, I get "Mpc" and "Rnbc" errors on the 82578DC, but no error > on the 82580. There is about 5 Mpc errors per seconds, and about 15 > Rnbc > errors per seconds. > > Embedded 82580 screenshot - with link to Intel LOM.jpg > http://i40.tinypic.com/35inm7b.jpg > > Intel LOM screenshot - with link to 82580.jpg > http://i44.tinypic.com/2q1f34o.jpg > > Is this somehow normal?? > > I also get Mpc and Rnbc errors on both my T60p laptop and the LOM NIC > when testing between them. Check those two screenshot: > Lenovo T60p screenshot - with link to Intel LOM.jpg > http://i41.tinypic.com/11l6k5t.jpg > > Intel LOM screenshot - with link to T60p.jpg > http://i40.tinypic.com/sfvswk.jpg > > > ----------------------------------------------------------------------- > ----- > > 3) When looking at the bandwidth values, they seems half of what they > should be on the 82580. > The 82580 total report ~1020Mbps and the partner (LOM) reports > 2046Mbps.... > > Embedded 82580 screenshot - with link to Intel LOM.jpg > http://i40.tinypic.com/35inm7b.jpg > > > Intel LOM screenshot - with link to 82580.jpg > http://i44.tinypic.com/2q1f34o.jpg > > Any explanation?? > > ----------------------------------------------------------------------- > ----- > > 4) The BER test between the 82580 and the LOM is failing in one > direction. > > BER screenshot between 82580 and Intel LOM - 82580 is RX.jpg > http://i44.tinypic.com/k9b86s.jpg > > > BER screenshot between 82580 and Intel LOM - LOM is RX.jpg > http://i42.tinypic.com/15qclfl.jpg > > > Tested at GigE speed > > Any suggestion of what to check?? > > Here is what I've checked so far: > - Mounted a 25MHz 2ppm TCXO oscillator (not xtal) on the 82580 > - 1000BASE-T Peak Differential Output Voltage and Level Accuracy > - 1000BASE-T Maximum Output Droop > - 100BASE-TX Differential Output Voltage (UTP) > - 100BASE-TX Waveform Overshoot > - 100Base-TX Rise and Fall Times > - 100Base-TX Duty Cycle Distortion (DCD) > - 100Base-TX Transmit Jitter > All of the test above at well within the limits specified in > "1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual" > > Using LANConf v1.18.8.1 under Win98SE DOS boot disk. > Cable is Cat5E STP (not UTP), 2 meter long, point-to-point > > ----------------------------------------------------------------------- > ----- > > > Thank you very much for you time, > > > Alexandre Desnoyers > Electronic Design Engineer > Qtechnology A/S > Valby Langgade 142, 1.sal - 2500 Valby - Denmark - www.qtec.com > > > > > ----------------------------------------------------------------------- > ------- > RSA® Conference 2012 > Save $700 by Nov 18 > Register now > http://p.sf.net/sfu/rsa-sfdev2dev1 > _______________________________________________ > E1000-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/e1000-devel > To learn more about Intel® Ethernet, visit > http://communities.intel.com/community/wired ------------------------------------------------------------------------------ RSA® Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
