The nbn website has helpful information for users accessing the Internet with nbn equipment during power outages. If you rely on your landline phone connection then you definitely need to understand what happens to the nbn equipment during blackouts.
Connected equipment over the nbn™ access network will not work during a power blackout. Below is more information about how each technology used in the nbn™ Multi Technology Mix (MTM) is affected by power loss.
Visit the nbn website for more details nbn equipment power outage customer support