0 transmitted messages

Gateways Raspberry Pi Gateways
1

Hi,

My GW receives messages (2.9K so far) but hasn’t transmitted any so far (0).
I’m quite suprised and it’s probably an obvious question or error of mine.

The machine is a Raspberry Pi with IMST iC880A, on european 868 mhz freq, my handler is ttn-handler-eu. It is behind a NAT but has unrestricted outgoing packet/connexion.

root@babelfish  (0) Wed Apr 24 13:11:45
/usr/local/ttnctl>telnet eu.thethings.network 1883
Trying 52.169.76.255...
Connected to eu.thethings.network.
Escape character is '^]'.

The packet routeur is sitting in memory:
root 476 0.6 0.1 18984 1760 ? Sl Apr18 59:54 /opt/ttn-gateway/packet_forwarder/poly_pkt_fwd/poly_pkt_fwd

Any idea?

2

Hi @kameo, your gateway is probably all ok.

The LoRaWAN network core decides which gateway to use for all downlink/transmit messages, usually based on the RSSI and SNR of uplink messages. If there are other gateways nearby then the core may be using them for downlinks.

Look at uplinks received from your sensors using the TTN console and the applications/data pages. You will be able to see the list of gateways that received the uplink from your sensors. Look at the RSSI for each gateway. The LoRaWAN core will use the best available downlink path.

Alternatively, if your sensors use ABP activation, unacknowledged uplinks and do not use ADR then there may never be any downlinks.

3

thanks a lot for this detailed answer, I’ll try with a connected object as proposed, but the explanation makes sense.

5

That port and protocol are not used by poly forwarder. Poly uses UDP on port 1700. Check for poll ack messages in the log. If not present that is an issue.