Reply To: Data synchronization error when processing VRT packets

Thanks for the quick response. It seems it’s always the network on most things. Before I posted, we had pretty much done what you suggested. One wrinkle I forgot to mention, the system running the packet capture code is a VM.

On my laptop and in our local lab the hypervisor is KVM. At our customer site it will be ESXi. My laptop is connected to a Sonnettech 10G SFP+ (Thunderbolt to SFP+) and our lab system is connected via SFP+ to a 10G/40G switch to the SH (all SFP+) – so we’re good there. On my laptop I used the suggested changes on my VM’s NIC as well as on my laptop NIC. Also note that the VM had to be changed to use an e1000e NIC rather than the virtio NIC – virtio does not take the NIC settings.

Here’s where it gets interesting I think: I spoke with another team who had similar issues and they suggested changing/adding some of the NIC settings to:

sudo sysctl -w net.core.rmem_default=67108864
sudo sysctl -w net.core.rmem_max=67108864
sudo sysctl -w net.core.wmem_default=67108864
sudo sysctl -w net.core.wmem_max=67108864
sudo sysctl -w net.ipv4.udp_rmem_min=4096
sudo sysctl -w net.ipv4.udp_wmem_min=4096

This seems to work (again, this must be set on all NICs) especially if we keep the sample rate to 25MS/s. I as able to run for over an hour. 50MS/s seems to be less error prone than before (run for 5-10min before a network error) but anything above that and we nearly immediately get the -6 error from smGetVrtContextPkt(). Better but still troublesome. I don’t know if making the max read/write to 64M or adding in the UDP setting helped? We’d like to get to 50MS/s if possible. Thanks again for the help.