Can server send donwlink in response to low level Keep alive uplink from End-node

I just want to confirm if there is way to send downlink messages on the basis of low level keep alive messages ie uplink that are coming from end node

To allow the application server to send downlink messages to our device if the low level keep alive does not allow the server to send an application level message then we still need this ping message to give the application this communication window. so the thing we need is that application level downlink window to be generated by the ping message.

I’m not sure if I understand the question, but ChirpStack does allow you to send back application payloads as part of the downlink. If you always want to get back a response from ChirpStack even if there is no application payload, then you might want to look into the confirmed uplink message-type or some of the mac-commands (e.g. link check).

Hi Brocaar,

Thanks for the prompt reply. Actually my query is: Mac layer of end node always keeps on pinging(send keep-alive message) to the chirpstack network server at some interval 1-2 min.
If the chirpstack app server would be aware of the lora keepalive ping that our end device sends out and if it is possible to use that to send downlink messages to our device. Else we should add some ping functionality for the same that after some specific interval we should send keep-alive ping message to server to make it possible to send back the downlink data(or some commands or queries) if available to be sent to device.

When you schedule a downlink, it will be kept in the downlink queue until there is a downlink opportunity / receive window. If your device sends a mac-layer only keep-alive (e.g. empty uplink / no fPort or fPort=0), then this is not exposed to the end-application, but it still this would create a downlink opportunity which can be used to send an application payload as downlink.