Tunneling Zigbee with ser2net and SSH

I wanted to deploy a network of Zigbee sensors in a remote location. The location had no "IT infrastructure" at all. The only connectivity available was LTE so I picked a modern router supported by OpenWRT - the Zyxel LTE3301-PLUS . My favorite Zigbee setup is Zigbee2MQTT and the Sonoff ZBDongle-P as it never caused me any trouble. There are various other Zigbee coordinators with Ethernet…