A few questions about downlink messages:
- Where are the messages actually stored (on the AS or NS; in memory, SQL, etc.)?
- I assume they are queued for transmission in FIFO order?
- How many can be buffered in the queue at once per device (i.e. is there a limit to the number of downlink messages that can be queued for a given device)?
- Does use of the ‘reference’ property (i.e. sending a second message with the same reference value) allow me to overwrite a message that is already in the queue (and has therefore not yet been sent)? And if so, does the “updated” message retain it’s position in the queue or is it moved to the end?
- Is there a way to remove/cancel a message from the queue?
PS - In this case, we are sending downlink messages via MQTT, but I assume that none of these answers would change for someone using the REST API?