NBN Co's own guidelines does say that you have to use an NBN approved modem, which the ones with the "NBN Ready" stickers are certainly.
The VoIP side of it is where the problems lies... Telstra's NGC validation system apparently is only guaranteed to work with the Telstra Gateways. When I was looking around at NBN plans I was told something similar by at least two other ISPs that I would have to use their gateway because it was the only one approved for their VoIP systems.
The VoIP side of it is where the problems lies... Telstra's NGC validation system apparently is only guaranteed to work with the Telstra Gateways. When I was looking around at NBN plans I was told something similar by at least two other ISPs that I would have to use their gateway because it was the only one approved for their VoIP systems.