I called my ISP... was on hold for 2h and their techie division had closed by time we got connected. So I've told the operator to get hold of a techie first and then call me back tomorrow evening.

Then the initial NBN technician called me back and told me that because our place is two-storeys, he cannot run wires under the house. And apparently there's a danger with running the wiring through walls. Anyway... awaiting a second opinion tomorrow.