Device address missing and downlink issue

Hi. I have two issues currently.

  1. I have created new devices in an application. After a while, I realized that my device address, network key and application key keep on missing (empty). I need to put again and reactive my device again. What’s the cause of this problem?

  1. I published a downlink from Chirpstack application. The downlink is available in Downlink Queue but does not show in Device Data and Lorawan Frame. It works fine few days back. Does the problem is on the server side or the hardware?

this is not a problem. this is session expiration
you can try to increase the value of device_session_ttl parameter in network server .toml
if your device hasn’t uplinks due this time, server automatically clear the keys etc.

Hi @eugenev. thank you for the reply.

  1. I couldn’t find device_session_ttl in chripstack_network_server.toml. Do I need to add this line manually?

  2. What about question (2) with regards to the downlink issue? Does it correlate with device_session_ttl as well?

Thank you.

if none, than yes, you need to add this line
for example device_session_ttl=“744h0m0s” this is 31day in hours after this ttl if device isn’t send any data, the keys are cleared.
about question N2, if device is not registered, app-server does not know to whom send downlink.

Hi… Yes… I have registered the device. However, the downlink doesn’t appear in Device Data as attached. I have deleted and added the device few times but it doesn’t resolve the problem. It works fine previously and out of sudden, it doesn’t work.

btw, this is the downlink that I sent.

if your device is class A, your downlink will be sent after uplink.

Thanks @eugenev. My device is Class A. Realized that I didn’t enable Class C in Device-profile. Thanks.