Multicast downlink LORAMAC_CRYPTO_FAIL_MIC


I’m using the newest LoRaMAC-node stack with the FUOTA example:

Then I’m using the Things Stack (newest version) on my local machine and a gateway (Raspberry PI + RAK831) connected to it.

I’m trying to set up a firmwareupdate over the air service for some labor tests at the university.

For the FUOTA server I’m using this server: GitHub - elsalahy/test-fuota-server: An experimental java script test server used for prototyping Firmware Updates Over the Air (FUOTA) on the Things Stack Cloud

The communication for the time sync + multicast setup and fragmented data block works fine. After the class c switch the server starts to send downlinks over the multicast device.

On the node I debugged it to the point where he checks the received downlink to the MIC and there it doesent fit.

I think it has something to to with all the key I have to provide for a multicast session.

Further, the example is for mac 1.0.3 version but I’m using the newest 1.1.0 version.

Could someone tell me what keys I have to setup on the device and what keys I have to provide on the server?

The example in the fuota server is using this setup:


But it is not mentioned what key’s I have to set for the mac 1.1.0 verion in the se-identity.h file of the LoRaMac-node stack.

Reading the specifications from the LoRa Alliance didn’t help…
It would be awesome if someone could provide waht steps on the node and what steps on the server have to be done, to communicate over the virtual multicast device.

kind regards,

Corsin Obrist

I provided an answer to this question at the following link

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