Although interest in them may increase, it’s unlikely any ZigBee coordinator that depends on a serial to Ethernet connection will be officially supported for ZHA.
At least one Home Assistant developer has explained that supporting them is complicated by their susceptibility to Wi-Fi latency. They rely on a serial to Ethernet connection (ser2net) and may be affected by communication delays thereby causing problems for ZHA’s operation (his comment was based on recent experiences supporting the Sonoff ZigBee Bridge).
I’ll post a link to his statement if I can find it.
EDIT
Naturally when I need to find the comment I can’t so all I can offer for now is the Warning in the ZHA documentation:
The EZSP protocol requires a stable connection to the serial port. With ITEAD Sonoff ZBBridge connecting over the WiFi network it is expected to see NCP entered failed state. Requesting APP controller restart in the logs. This is a normal part of the operation and indicates there was a drop in communication between ZHA and SonOff bridge.
The background for the Warning message is the issue I had mentioned: serial to Ethernet connections are susceptible to Wi-Fi latency and may cause stability issues.
Should again take note that the Sonoff ZBbridge is not recommended for production with external “client” implementations using the EZSP serial protocol such as Zigbee2MQTT, ioBroker, or ZHA in HA.
The reason Ember remote bridges over serial-to-IP proxy server is not recommended is that clients using the EZSP serial protocol requires a robust connection between the EmberZNet Zigbee stack running on EFR32 MCU and the serial port of the Zigbee radio. With solutions such as ITEAD Sonoff ZBBridge or a Ser2Net serial proxy connection over a WiFi network it is expected to see NCP entered failed state. Requesting APP controller restart in the logs. This is a normal part of the operation and indicates there was a drop in communication which caused packet loss to occurred between the zigpy radio library and the Zigbee radio. The use of serial network proxies/bridges/servers over WiFi is therefore not recommended when wanting a stable Zigbee environment with Silicon Labs Ember based Zigbee radios. The developers of the bellows radio library for the zigpy project has more information about this if needed.
No such WiFi bridge is recommended when Silicon Labs EZSP. Compromise if really need a network bridge could to switch to an wired Ethernet bridge instead of WiFi but it is still not an optimal solution
Initial development started on experimental (pre-alpha stage) support for various adapters based on Silicon Labs EFR32 SoC families with EmberZNet NCP 6.7.8 firmware or later via EZSP version 8 (EmberZNet Serial Protocol) interface. This include all hardware based on SoCs/Modules from Silabs EFR32MG21/MGM210 and EFR32MG12/MGM12 series.
Support for the Conbee II (discussion), ZiGate USB-TTL (discussion), and Silicon Labs EZSP (discussion) is experimental, meaning not feature complete nor recommended for a stable enviroment.
FYI, EZSP adapter should work with all of these once have updated to Silicon Labs EmberZNet 6.7.x coordinator firmware or later:
Sonoff ZBBridge Zigbee WiFi Bridge gateway re-flashed with Tasmota (though it not recommended since EZSP over WiFi connection does not make for a stable solution)
