Zigbee end device with low RSSI removed from the network

[Laura M]

Hello,

we implemented Zigbee coordinator. Few end devices left the network and we know that the issue is our side because the same devices work well with other coordinators.

This issue is rare and it happens only with devices that were reporting low RSSI values (we don't know how to replicate the issue and we have no logs).

This issue is similar to the one described here but there is no conclusion there.

We use nrf52840 with nrf5 sdk for thread and Zigbee v4.2.0 without soft device library.

We have the following questions:

1. Are you aware of any known issue related to described behaviour, with this SDK?
2. Recently we added the management of ZB_ZDO_SIGNAL_DEVICE_UPDATE in the case where status is ZB_DEVICE_LEFT (zb_zdo_signal_device_update_params_t), previously we just ignored this signal. Can this be the issue?
3. Can this signal be triggered even if there are no routers in the network?

Best regards.

Laura

[Laura M]

Hello Elfving,

Elfving said:

So is the Coordinator the nRF running our Zigbee stack, and the ZEDs are not?

yes, correct. ZED doesn't implement Nordic Zigbee stack.

Elfving said:

It does seem a bit similar to KRKNWK-12017

It doesn't seem related in my opinion. The workaround you suggested is intended for a ZED and it activates if signal ZB_ZDO_SIGNAL_LEAVE is triggered. Here instead we implemented Zigbee coordinator (ZC) and signal ZB_ZDO_SIGNAL_LEAVE "is generated when the device itself has left the network by sending leave command" (as per Nordic documentation). So this signal doesn't seem related to our scenario.

Let me know if you don't agree with my previous statement or if you have any other hint.

Thank you.

Laura