NBN and phone only...what did the provider install?

[VK4AN]

The consumer is not powering the NBN FTTN system. When the power goes out your system won’t work with a UPS, because the MSAN in the cabinet won’t have power from the local grid that is direct connected. FTTC is usually powered off the modem as the DPU (often Nokia kit) by the consumer, and it’s GFAST capabilities are not turned on at this stage, it’s hardly EOL equipment. FTTC will not work in a power outage with a UPS unless most of the users on the DPU have such a setup, as the reverse power is load balanced across subscribers.

If you are getting interference then I would suggest the first step is to put in a central splitter.