Hi,

I have just purchased the Deco M5 system. The house is three floors, double cinder-block brick with concrete floors, so WiFi signal struggles to penetrate from room to room. Each room is however wired with ethernet ports. I want to use the house ethernet ports to plug in the Deco's, rather than relying on connecting them to each other via WiFi. The current setup and planned setups are below, can you please tell me if my planned setup is correct, or if there is an easier way plz let me know. I don't have a switch and would need to buy one if that is the correct setup. 

Questions:

Note: In Australia we have a new National Broadband Network (Nbn) and this house was only recently converted over to it. I don't want to mess around with my supplier's (Telstra) Smart Modem that's plugged into the Nbn box, or the Nbn box if I don't have to because it took the three Telstra technicians to get everything working after the Nbn guys came around and installed the Nbn box.

1. There's a WiFI button on the Telstra Smart Modem - do you think it will be ok to just use that to switch off it's WiFI or should I login to the box and find the setting?
2. Do I need the switch as per the Planned Setup below or can I just plug everything into the Telstra Smart Modem?
3. If I do need a switch, can I use an old WiFi router with WiFi turned off instead of a switch?
4. Do I run the main deco in Access Point (AP) mode or Router mode?
5. How can I be sure the Deco's connect to each other via ethernet and not weak WiFi?
6. Any setup tips / pointers e.g. do I need to set up Deco 1,2,3,4 via wifi in the basement, do a firmware upgrate on them, then go upstairs and plug them in, or just go for it as planned, go straight to the ethernet ports and press "find" on the app. 

Thanks 

MC.