Problem with duplicated packets

Good afternoon! I have the following setup:

1 x kerlink Wirnet iStation (LoRaWAN GW): Wirnet iStation - Kerlink
1 x Microchip RN2903 based Wireless Board (LoRa node): RN2903 - Wireless Modules

Also, I have an Application Server running here at thethingsnetwork.org_.
However, for some reason, I see duplicated packets at Application Server level.




I am running a small program in the node sending fake Tº, incrementing them by one in each packet sent (so, If I have the same Tº in two packets, it means they are duplicated).

PD: For some reason I see that duplicated packets have different frequencies and channels, but I cannot find an exact pattern neither explain why.

Could you please explain why this is happening and if ii is correct or not? What can I do to filter these duplicated packets at gateway (remember that I have only one gateway) or at Network Server level?

Thanks in advance!

You are using confirmed uplinks and the node does not receive the acknowledgment. As a result it keeps retrying.
You should not filter these messages, you need to make sure not to use confirmed uplinks… also investigate why downlinks seem not to work.

Good afternoon and thank you for your answer! How can I configure my setup not to use confirmed uplinks? Also, could you guide me through first steps to diagnose the problem with downlinks?

That should be a setting in the software on the node talking to your RN2903.

Start by scheduling a downlink in the console (make sure not to use confirmed!), then have the node send an uplink at which time the downlink should be sent to the node. What happens on the node depends on what software is running on it.
Make sure to keep at least 10 feet (and preferably a brick wall) between the gateway and the node to avoid overloading sensitive receiver circuits.

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Great! Thanks for the info I am going to do some tests and get back to you as soon as I can.