You have to wait as the initial connection must be made with an Optus NBN modem/router. Only after that can you switch to the TP-Link.
Note that none of the Optus NBN services require a username/password for internet access, so when you end up connecting the TP-Link you just need to use a WAN connection type of IPoE/Dynamic IP/Automatic IP or DHCP.
Thanks, do I need to use the one they send or could I pick up a second hand one of the same model and use that to set up.
As far as I'm aware you can use any, not just the one they have assigned to you. The supported models are Sagemcom F@ST 3864 series, F@ST 5366, and the new "Ultra WiFi modem with 4G back-up". The 3864 are the oldest and therefore should be cheapest 2nd hand.
There is also the matter of activation notification. Everything I've seen so far indicates that even with the right modem you can't activate the service until you get formal notification from Optus, usually by SMS, that your service is activated/provisioned.
Thanks, I was just reading up on that and you're right.
I think its right but I am getting mixed messages. I have requested clarification from Optus but already have a few questions outstanding with them.