When the NBN technicians contact you to discuss setting up your connection, they’ll inspect your property and offer several possible locations for the equipment. This includes an external utility box, and an internal connection box (with an optional battery backup).
Some people find that the exterior box affects the aesthetics of their home, and that the lights on the internal box can be visually distracting or annoying. For these reasons, you might want the NBN boxes to be hidden or in less visible places around your building.
While you can request a specific location, the final decision is the installer’s, as the layout of your home, wiring, and router will determine the viable installation points. It’s also not possible to install a connection box in a wet area, like a bathroom or laundry, for safety reasons.