Class C device adding confirm downlink to queue


I am sending confirmed downlink to my Class C device But server is adding confirm downlink to Downlink queue .

Currently Using -

chirpstack-application-server version - 3.7.0-1-g6a9c690
chirpstack-network-server version - 3.6.0-2-g1d66d30
chirpstack-gateway-bridge version - 3.6.0

Device profile configuration - Class C, RX2 data-rate - 3, LoRaWAN MAC version - 1.0.1, LoRaWAN Regional Parameters revision - A

I’m facing this problem on my different chirpstack server versions which was working fine before and I did not made any changes. Now I have successfully restarted all services yet still facing the same issue.

Please Guide.


@brocaar please help.

Hi, I am facing same problem.
Only difference is, that I use OTAA.

Whenever I want to make a downlink, it will be scheduled.
On next regular uplink, downlink will be send.

Any help or hints would we great!


Hi. I am facing the same problem. Is there really no solution?

Hi, still have the problem.

Maybe some further questions (from Device-classes - ChirpStack open-source LoRaWAN® Network Server

  1. “ChirpStack Network Server supports Class-C devices and uses the same Class-A downlink device-queue for Class-C downlink transmissions.”
    Does that mean, that a downlink like a normal confirm also goes in the queue? Or is the queue exclusive only for triggered downlinks?

  2. “[…] Until the frame has timed out, ChirpStack Network Server will wait with the transmission of the next downlink Class-C payload.”
    I assume it is per device, right? So, if I would have x devices and sending downlinks to every device, than chirpstack will not wait for response or timeout from one device and all other have to wait for it, right?