What are the messages after Join Accept?

[guillebot]

Hi there. I apologize in advance, I’m new to LoRa and this must have been talked about lots of times, but I can’t seem to find it.

I’m using Chirpstack v4, with an Arduino+mcci+catena node. I’m in Argentina so AU915 it is.

Everything is working amazing so far, but in the process of writing my decoders I found that after the join, there are several (about 10) messages with fPort=0. At some point I found out that they are MAC messages between Chirpstack and the Node and I’m now skipping them on the decode.

But I would like to know more about those messages, what are they? How can I understand the information? etc. Can anyone give me some pointers of what to read? Are they part of the rate negotiation?

Thanks in advance

Guille

[brocaar]

@guillebot

But I would like to know more about those messages, what are they? How can I understand the information? etc. Can anyone give me some pointers of what to read? Are they part of the rate negotiation?

You can inspect these messages when you go to your device in the web-interface and click the LoRaWAN Frames tab.

Most likely these frames contain ADR commands to tune the device data-rate and tx power.