Multicast transmission period


I’m doing some tests with Multicast and noticed that the multicast queue gets drained rather slowly, like 1 message every 6 seconds. Is there any way to speed up the dequeuing of the multicast queue? Maybe once every 2 seconds?

The payload is around 50 bytes and the datarate is 8 (US902). There are currently around 40 devices configured in the multicast group but there will be thousands soon.


just calculate how long it will take to send the maximum length packet with this data rate. the application server initially does not know about the length of the packet that you are going to send via the multicast group in order to change time slices on the fly to avoid overlaps.

Hi Eugene, thanks for the reply.

The time is less than 0.5seconds pero packet but still the packets only get set once every 6 or so seconds from the Server queue. If I enqueue for example, 20 packets, they will get sent once every 6 seconds, even though the air time for each packet is much lower.

What I want to find out is if there is a way to speed up this queueing process on the server so that it dispatches the queued messages faster.


I meant max. allowed LoRaWAN packet length at all, not specific to your case

Hi Eugene,

sorry, still not clear on what you mean. Could you please elaborate a bit more so that I can understand?

Thanks you!

what is the values of scheduler_interval= and downlink_lock_duration= in your chirpstack-network-server.toml ?

Hi Eugene,

Actually I don’t have any of those settings in my chirpstack-network-server.toml so I think it’s using the default values.

Maybe that is the issue?


what’s stopping you from trying?
for you, developers have created a description of the parameters in the configuration file

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Hi Eugene,

super useful, that was just what I was looking for.