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For the NBN FTTP technology, you need a router that is NBN ready to be connected directly to the NBN NTD box.
If the Google nest mesh bundle that you are going to purchase has a router capability, then it can be connected directly to the NBN NTD box.
You just need to configure it with the correct PPPoE Username and Password (TPG credentials).
You may use this article as a guide only: How to set up TP-LINK C1200 modem for Windows 10