Yes, WAN I mean over the internet, because in my "final vision" I want to have conectend more GWs from different buildings to the same controller. So is GW<->controller comunication somehow secured? Or is better to use MQTT? Or there should be always a VPN connection for sure in safety? It is possible to connect multiple Domoticz instances, see https://www.domoticz.com/wiki/Setting_up_Device_sharing I have not tried it and I don't know how secure it it but it might be a good solution, but requires a Raspberry Pi or similar in each location. Mqtt gateway with TLS and username+password could be a good solution. VPN or ssh tunnel should work but will require extra hardware (support in router or a raspberry pi in each location). I have one more question - in manual how to make a ethernet GW is an option to choose W5100 or ENC28J60 module. Is there any significant reason why to choose W5100 when its price is almost 2x higher than ENC? Yes. If you value your time at more than 50 cents per hour The enc28j seems to be much less stable.