Frame count error

Hi Guys,

Does anyone have any knowledge regarding this error in my device data?

@brocaar Please let me know if your thoughts. Thank you.


Are you sending confirmed uplinks?

Do you have multiple gateways where one might somehow have very laggy connection to the server, such that you’re really seeing the same actual transmit emission, tardily reported in again long after the fact?

Could also be a bug in the node firmware - or an illicit hack on the lorawan spec, eg there are apparently some firmwares that duplicate uplinks automatically.

Would be worth looking at all the details of both the original instance of that frame count and the repeat.

This error basically tells you that the NS already have seen an uplink with the same frame-counter. It could be that this is because the device is sending the same uplink multiple times or because of a replay-attack.

In either case, the NS will reject it because it was already processed.