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ahaa's avatar
ahaa
Icon for Occasional Contributor rankOccasional Contributor
4 years ago

How to make N3000 support jumbo frames?

We want to change the configuration of N3000-2/N3000-1 to make the card support jumbo frames（larger than the default size 1518B，1519B-9000B）. Now we have tried to modify application of dpdk such as skeleton basic forward or l2fwd，and it makes sense.

When tested the dpdk application on other NIC cards，it could receive and transmit jumbo frames. However，in the card of N3000-2（2x2x25G），it could only receive jumbo frames without transmitting .

We also did another test to connect ing_in* signal with egr_out* signal to make an internal lookback. The result shows it can’t transmit jumbo frames.

According to our analysis, it is most likely that there are some configuration changes in Arria10 , IP or some relevant registers.

Anyone knows how to do or any advice?

11 Replies

    • ahaa's avatar
      ahaa
      Icon for Occasional Contributor rankOccasional Contributor
      4 years ago

      Thanks for your reply!

      Actually we have checked the size of MTU of wrapper and modified it to 9600. The MTU of XL710 would be returned to the default value 1500 even though we set it to 9600 after bounding to vfio-pci driver in the mode of DPDK . But we could receive jumbo frames.

      The problem is the card can not forward jumbo frames.

      Using signal-tap we captured some signals and found that egr_out* signals are correct. Based on this, we can deduce XL710 and DPDK have no problem. So we think that there may exist some configurations in the path of egr_out* to QSFP, which limits the forwarding of jumbo frames.

      In the other experiment, we connected the ing_in*----egr_out* directly, and the forwarding of jumbo frames failed too. I think this is further confirmation that our consideration is right. The bottleneck is between egr_out and QSFP, and that's exactly what corresponds to nfv_eth_wrapper, mux, demux and some other modules in RTL project.

    • ahaa's avatar
      ahaa
      Icon for Occasional Contributor rankOccasional Contributor
      4 years ago

      Thank you for your continued attention.

      We have found that some dpdk application can fully support giant frame and we ported the related functions to other applications. So far the issue with giant frame support has been resolved.

      • JonWay_C_Intel's avatar
        JonWay_C_Intel
        Icon for Frequent Contributor rankFrequent Contributor
        4 years ago

        Thank you for the update. Would you share with us what is the dpdk application and how you used it to support jumbo frames? I think it will be a good learning for all other forum users as well.