Downlink frames saved before they could be sent

Hi,

I am facing an issue with downlinks, device class A ABP authentification. I never see, DataDown on the application. Considering the journals, it seems that the network-server can’t transmit the downlink to the gateway-bridge. I can see that the debug messages “device-session saved” and then “downlink-frames saved”.

The device is configured correctly and the Confirmed Uplinks appear, but I never got a confirmed nor unconfirmed data Down (I tried setting a downlink manually, it doesn’t change) :

The App Server journal says everything is ok :

May 01 18:08:52 DomoticzServerPCPlus chirpstack-application-server[27936]: time=“2020-05-01T18:08:52+02:00” level=info msg=“integration/mqtt: publishing message” ctx_id=d813151e-bcf7-4ad0-8159-5f8decc2ee8d qos=0 topic=application/1/device/a8dd6df57239f322/rx
May 01 18:08:56 DomoticzServerPCPlus chirpstack-application-server[27936]: time=“2020-05-01T18:08:56+02:00” level=info msg=“device last-seen and dr updated” ctx_id=dced9a36-261f-4c73-85ca-d21670fedaf9 dev_eui=a8dd6df57239f322
May 01 18:08:56 DomoticzServerPCPlus chirpstack-application-server[27936]: time=“2020-05-01T18:08:56+02:00” level=info msg=“finished unary call with code OK” ctx_id=dced9a36-261f-4c73-85ca-d21670fedaf9 grpc.code=OK grpc.method=HandleUplinkData grpc.request.deadline=“2020-05-01T18:08:57+02:00” grpc.service=as.ApplicationServerService grpc.start_time=“2020-05-01T18:08:56+02:00” grpc.time_ms=17.074 peer.address=“127.0.0.1:56178” span.kind=server system=grpc
May 01 18:08:56 DomoticzServerPCPlus chirpstack-application-server[27936]: time=“2020-05-01T18:08:56+02:00” level=info msg=“integration/mqtt: publishing message” ctx_id=dced9a36-261f-4c73-85ca-d21670fedaf9 qos=0 topic=application/1/device/a8dd6df57239f322/rx
May 01 18:09:09 DomoticzServerPCPlus chirpstack-application-server[27936]: time=“2020-05-01T18:09:09+02:00” level=info msg=“device last-seen and dr updated” ctx_id=47271da6-65a8-4c57-ad11-b26d96e81ab1 dev_eui=a8dd6df57239f322

The Network Server activates the downlink (it is supposed to wait for one second but it doesn’t always) :

May 01 18:08:57 DomoticzServerPCPlus chirpstack-network-server[6865]: time=“2020-05-01T18:08:57+02:00” level=info msg=“pending mac-command block set” cid=RXTimingSetupReq commands=1 ctx_id=36c7d690-2da8-494b-8c71-e477f707de7f dev_eui=a8dd6df57239f322
May 01 18:08:57 DomoticzServerPCPlus chirpstack-network-server[6865]: time=“2020-05-01T18:08:57+02:00” level=info msg=“gateway/mqtt: publishing gateway command” command=down downlink_id=36c7d690-2da8-494b-8c71-e477f707de7f gateway_id=0281f6ffffcba069 qos=0 topic=gateway/0281f6ffffcba069/command/down
May 01 18:08:57 DomoticzServerPCPlus chirpstack-network-server[6865]: time=“2020-05-01T18:08:57+02:00” level=info msg=“device-session saved” ctx_id=36c7d690-2da8-494b-8c71-e477f707de7f dev_addr=7d140126 dev_eui=a8dd6df57239f322
May 01 18:08:57 DomoticzServerPCPlus chirpstack-network-server[6865]: time=“2020-05-01T18:08:57+02:00” level=info msg=“downlink-frames saved” ctx_id=36c7d690-2da8-494b-8c71-e477f707de7f token=14023

But in the GW Bridge, nothing happens, only uplinks and Acks… :

May 01 18:08:56 DomoticzServerPCPlus chirpstack-gateway-bridge[27306]: time=“2020-05-01T18:08:56+02:00” level=debug msg=“backend/semtechudp: received udp packet from gateway” addr=“127.0.0.1:44448” protocol_version=2 type=PushData
May 01 18:08:56 DomoticzServerPCPlus chirpstack-gateway-bridge[27306]: time=“2020-05-01T18:08:56+02:00” level=debug msg=“backend/semtechudp: sending udp packet to gateway” addr=“127.0.0.1:44448” protocol_version=2 type=PushACK
May 01 18:08:56 DomoticzServerPCPlus chirpstack-gateway-bridge[27306]: time=“2020-05-01T18:08:56+02:00” level=info msg=“integration/mqtt: publishing event” event=up qos=0 topic=gateway/0281f6ffffcba069/event/up uplink_id=a2397ca9-c733-4dc7-b59a-90382587f15b

The MQTT Broker however sees the downlink published “sudo mosquitto_sub -t gateway/0281f6ffffcba069/command/down”:

{“phyPayload”:“YCYBFH2nDQAFANKthAgBhv3PtA==”,“txInfo”:{“gatewayID”:“AoH2///LoGk=”,“frequency”:868099975,“power”:14,“modulation”:“LORA”,“loRaModulationInfo”:{“bandwidth”:125,“spreadingFactor”:7,“codeRate”:“4/5”,“polarizationInversion”:true},“board”:0,“antenna”:0,“timing”:“DELAY”,“delayTimingInfo”:{“delay”:“1s”},“context”:“xbonew==”},“token”:51053,“downlinkID”:“x21EeUaLST2cJNH6w5wEtw==”}

But I can confirm with an SDR that no downlink is sent 1second later.

It’s like the chirpstack-gateway-bridge.toml was misconfigured and didn’t listen to command/down but it seems like it does, or am I missing something ?

marshaler=“json”
[integration.mqtt]
event_topic_template=“gateway/{{ .GatewayID }}/event/{{ .EventType }}”
command_topic_template=“gateway/{{ .GatewayID }}/command/#”

At that point I have no more clue where to look at, do you :thinking: ? Any help would be appreciated.

BTW, the OTAA gives the same kind of result : there is an Accept OK and Keys updated generated by the Network Server, but none of this is transmitted to the GW Bridge, so there never was a Join Accept on the Chirpstack Server.

Kind regards,
Nico