Issues with downlinks after upgrading

ChirpStack Network Server
1

Hi there

I have a problem with ADR and after starting to debug I realize the server simply isn’t sending the scheduled downlink either (thus I imagine so mac commands)
I put some data on downlink scheduler, send an uplink, the queue is flushed but on LoRaWAN Livedata there is no downlink.
On MQTT, I can’t see any message on any other topic besides on event/up from application.
I can see messages on command/down from network server

I notice one another strange thing, I use RX1 delay of 5 seconds set on NS env var NETWORK_SERVER__NETWORK_SETTINGS__RX1_DELAY=5

The NS is not taking into account the RX1 Delay and sending the downlink within 1 second.

T: 2021-03-05 19:31:30

{
	"phyPayload": "QAHk/xeAEwEBXi9GOAkCvZ2yUxVnnNoFgm1n5dzasuI=",
	"txInfo": {
		"frequency": 916200000,
		"modulation": "LORA",
		"loRaModulationInfo": {
			"bandwidth": 125,
			"spreadingFactor": 12,
			"codeRate": "4/5",
			"polarizationInversion": false
		}
	},
	"rxInfo": {
		"gatewayID": "cHb/Aqyy/wA=",
		"time": "2021-03-05T19:31:30Z",
		"timeSinceGPSEpoch": null,
		"rssi": -69,
		"loRaSNR": 10.2,
		"channel": 5,
		"rfChain": 1,
		"board": 0,
		"antenna": 0,
		"location": null,
		"fineTimestampType": "NONE",
		"context": "AAM5hA==",
		"uplinkID": "Bz/zA7LGTzS98KyMUKQv5g==",
		"crcStatus": "CRC_OK"
	}
}

T: 2021-03-05 19:31:31

{
	"phyPayload": "YAHk/xePOAADAAEAcANg/wABBQho4oxCMfiu",
	"txInfo": {
		"gatewayID": "cHb/Aqyy/wA=",
		"frequency": 926300000,
		"power": 27,
		"modulation": "LORA",
		"loRaModulationInfo": {
			"bandwidth": 500,
			"spreadingFactor": 12,
			"codeRate": "4/5",
			"polarizationInversion": true
		},
		"board": 0,
		"antenna": 0,
		"timing": "DELAY",
		"delayTimingInfo": {
			"delay": "5s"
		},
		"context": "AAM5hA=="
	},
	"token": 27324,
	"downlinkID": "arzSwaOkQg+GDKAnH7Hotw==",
	"items": [{
		"phyPayload": "YAHk/xePOAADAAEAcANg/wABBQho4oxCMfiu",
		"txInfo": {
			"gatewayID": null,
			"frequency": 926300000,
			"power": 27,
			"modulation": "LORA",
			"loRaModulationInfo": {
				"bandwidth": 500,
				"spreadingFactor": 12,
				"codeRate": "4/5",
				"polarizationInversion": true
			},
			"board": 0,
			"antenna": 0,
			"timing": "DELAY",
			"delayTimingInfo": {
				"delay": "5s"
			},
			"context": "AAM5hA=="
		}
	}, {
		"phyPayload": "YAHk/xePOAADAAEAcANg/wABBQho4oxCMfiu",
		"txInfo": {
			"gatewayID": null,
			"frequency": 923300000,
			"power": 27,
			"modulation": "LORA",
			"loRaModulationInfo": {
				"bandwidth": 500,
				"spreadingFactor": 12,
				"codeRate": "4/5",
				"polarizationInversion": true
			},
			"board": 0,
			"antenna": 0,
			"timing": "DELAY",
			"delayTimingInfo": {
				"delay": "6s"
			},
			"context": "AAM5hA=="
		}
	}],
	"gatewayID": "cHb/Aqyy/wA="
}

I did upgrade NS from 3.10 to 3.12.2.

Question:
Why the downlink is not showing on application live frames ?
What can I to make NS to respect the RX1 delay set on config ?

Any hint where can live that problem ?

Thanks

2

Hi Giulio,
the second log that looks like what gateway/<gatewayID>/command/down topic would show which literally commands the gateway to send downlink. That has to happen earlier than your RX1 windwow, so 1s after uplink is ok (even seems quite long to me here, but it can be rounded up).

You can also see the "delay": "5s"and "delay": "6s"values there which is your RX1 = 5s and RX2 = RX1+1s windows.

After that the gateway should send gateway/<gatewayID>/event/ack which tells the downlink was SCHEDULED to transmission. Older packet-forwarders does not send this ack in which case the AS will not show a downlink in live frames anymore (that was different few versions ago).

So to me it seems your gateway does not send the ack for downlink in which case the NS does not know if it has been scheduled by gateway or not, so it is considered as scheduled I think.

3

Hi @martin

Thanks for your feedback.
I understand what you mean. What bothers me is the fact that I did receive de ACK before. My gateway does send that (i use semtech pkt fwd).

After restarting the NS I could get again the ACK and Downlink frame. With 5s delay.

Don’t know, but for some garbage or cache it stops working as usual.

Thank you again for your feedback, I will keep my eyes on it.

cheers