Multiple Zigbee Report packets sniffed

[sjf]

Hi,

We have been working with a coordinator and a router device based on nRF52840 with nRF5_SDK_for_Thread_and_Zigbee_v4.0.0_dc7186b

Both devices are Zigbee 3.0 and implement Install Codes.

The router and end devices report periodically to the coordinator. After some time and power reconnections the sniffer starts to show that the same ZCL Report Attributes (same content, same Seq Id) is sent multiple times. 

If the device is reset, there is no change. In fact, it seems to increment the number of packets with the same content.

Why is this generated? Is it a well known issue?

Thanks in advance,

Santiago

log_report_multiple_packets_issue_20200831.pcapng

[Kenneth]

Hi,

I will check with the team, let me know if you have any new findings.

Kenneth

[sjf]

Thanks Ken.

Could this be related to a wrong setting of PA/LNA? Coordinator is running in a BT840X module with embedded PA/LNA module.

[Marjeris Romero]

Hi,

It's normal for the MAC and NWK layer to retransmit a packet if the device that sends a frame has the acknowledgement request field set to 'True' and the apsAckWaitDuration expires before an acknowledgment is received (this means that the data transfer has failed). Retransmission of a packet is covered in the Zigbee specification:

You can see from the sniffer trace that you are not receiving a APS ack response from the coordinator when you send the Report attributes command, while the 'Acknowledgement Request' field is set to 'True':

BR,

Marjeris

[Marjeris Romero]

Hi,

The PA/LNA configuration could be an issue, it can also depend on how far the router and the coordinator are from each other.

Another thing I notice is that if you look at the frame 32 in the sniffer trace I can see that the coordinator is sending a packet to a different PAN ID address, so it looks like there are actually 2 networks? But in frame 31 the coordinator sends a link status to the same destination PAN ID as the router (0x3fc3). Have you seen the log output from the coordinator? Perhaps the coordinator has an assert or somehow failed and opened a new network?

Best regards,

Marjeris

[sjf]

Hi, It seems that the PA/LNA was incorrectly enabled for both BLE and Zigbee and that was the root cause of this issue.

Thanks in advance for your helpful support.

Regards,