Debug failed join request on gateway

[laurent brunet]

Hello,

I’ve already gone through some testing with an mdot box joining a multitech conduit : AEP and sending information to it, everything is working fine.

Now, I’m trying to use my own device that has a sx1276 to try and join the gateway. I’m currently unable to join and want to start debugging.

Is there any way to obtain information regarding failed join attempts the gateway received and try to go from there to see what’s happening? I know my device is emitting at the right time using a spectrometer.

Thanks a lot!

[Peter Ferland]

Unfortunately the very low level logging that you’d need for this is not available.

The most common issue with third party devices is that by default the Conduits are in a “private” network configuration with the sync word set to 0x12. Unless configured differently, most LoRa devices will expect the sync word 0x34 which is the “public” network configuration.

On an AEP conduit you can change this on the “LoRa Network Server” page by checking the “Public” box.

[laurent brunet]

My gateway is already checked for Public network. I’ll just look at the lora-network-server.log to see what the gateway is receiving and maybe I’ll be able to go from there.

[Jason Reiss]

Using node-red one could use a mqtt listener subscribed to lora/+/+ to get all messages from the network server.

In the lora configuration page the network server can log to a file instead of syslog. Set log level up to trace or maximum for the most output.

Access the log through an ssh connection to the conduit or via node-red using a tail node with the file location connected to a debug node.

This code will read from mqtt and a /var/log/lns.log file.

[{"id":"833b749b.e3f0f8","type":"mqtt-broker","broker":"localhost","port":"1883","clientid":""},{"id":"6f3bd636.e3358","type":"debug","name":"","active":true,"console":"false","complete":"true","x":647,"y":208,"z":"d4e998f8.a27b","wires":[]},{"id":"726b607d.1fd1d","type":"mqtt in","name":"","topic":"lora/+/+","broker":"833b749b.e3f0f8","x":395,"y":103,"z":"d4e998f8.a27b","wires":[["6f3bd636.e3358"]]},{"id":"cee8454f.de77b8","type":"tail","name":"","split":true,"filename":"/var/log/lns.log","x":504,"y":47,"z":"d4e998f8.a27b","wires":[["6f3bd636.e3358"]]}]


[laurent brunet]

I’m using tail -f /var/log/lora-network-server.log to monitor what’s happening on the gateway.

When I transmit with my device I have the information saying the Rx frequency, rssi and snr.

Then I have a warning saying MessageRejectException : Message received from unknown node.

Got any idea what I should be looking at from there to see why it’s rejected?

[Peter Ferland]

Are you trying an OTA join or a manual join? It sounds like your device is sending a manual join request and the node is not already known by the Conduit.

To set up a manual join you’d have to follow the mLinux instructions on this page: http://www.multitech.net/developer/software/lora/conduit-mlinux-lora-communication/conduit-mlinux-lora-use-third-party-devices/
(this will work on an AEP conduit – the only difference is that the username will be admin)

[laurent brunet]

Yep that was the case! Step by step getting closer thanks to your help! So big thank you to you both.

It seems like my packet is received by the gateway. They do not make their way to my node-red flow though. I can see the packet information in my debug window but it seems to fail after reporting Mic check : fail.

Any idea?

Here’s the full log : Log

• This reply was modified 7 years, 3 months ago by laurent brunet.

[Peter Ferland]

Double check that the AppSKey you entered for the node matches what you’re using to encrypt the payload on the device.

[laurent brunet]

I don’t know if it did. I removed the node from the gateway and re-added it and it now works so it might be exactly why.

On the off chance that it wasn’t. Is there any lease time or something like that, that might trigger this mic check fail after I added the node to the gateway?

Thanks!

[Peter Ferland]

By default leases do not expire. Even if you changed the lease time option it will not change the session keys – you’ve hard coded them through the manual join process.

[laurent brunet]

That’s good to know, thanks for the help!

[laurent brunet]

For some reason, every now and then my added nodes disappear from my gateway. Anything that might cause this?

Thanks!

• This reply was modified 7 years, 3 months ago by laurent brunet.

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