I’m using gateways RAK7289CV2 (about 70 when the project will be finished), we are using them with chirpstack and UDP forwarder to have the buffer.
We see that when the buffer is released after an LTE connection is back, they arrive in disorder and some are missing. How many frames, the GW can store ? Why those disorders ? It should be FIFO from my point of view.
Also, I don’t understand why not to do under Basic station or MQTT protocol, is this hard to implement this ? I’m surprised that there is not more complain about bufferization, so important with micro cut of LTE or outage ?
Have a nice day all. Would be great if someone knows more about his topic !
To precice that we don’t care id arriver before or after, we did tick the “Disable frame-counter validation” on chirpstack, our company monitor things not especially in live, tha past events are also important for our clients.
The buffering time is limited by Keepalive interval * Auto-restart threshold. If keepalive fails beyond that window, the Packet Forwarder restarts and buffering stops. For more information, you can refer to this document - WisGateOS 2 User Manual | Complete Guide for LoRaWAN Gateway Software
Even though the gateway replays the stored frames later, the LNS receives them after it has already processed newer uplinks (higher FCntUp). Assuming that if validation is disabled, the frames are accepted, but the processing order is still based on arrival time, not on the original timestamp.
The UDP based packet forwarder can buffer data because the forwarder and the radio hardware layer continue operating even when the network connection is lost. In contrast, LoRa Basics Station relies on a secure, session-based connection over TCP and WebSocket with TLS. When this connection drops, the Basics Station forwarder stops immediately and the radio layer stops as well, so there are no incoming uplinks to store. MQTT ensures reliability through its own QoS mechanisms.
Thanks a lot for your message ! I understand much more now.
Do you think that for micro cut (less than 10 secs), the basic station or MQTT could resend the messages not arrived to the server ?
Have a nice day !
Basics Station will immediately disable the radio device when the connection is lost, whereas I think MQTT can do it with QoS 2 (Exactly Once) and optionally Retain.