Battery back-up mandatory for NBN?

Are backup batteries being provided to all NBN customers as the Minister for Communication claims, or are these a customer installed option, as the NBN documentation states?

On ABC Radio in 2009 I stated that:

"One thing the NBN needs is a battery backup lasting at least 4 hours, so the system keeps running in an emergency. Failing to design the system for this would be unethical for ICT professionals involved in the project. The responsible decision makers involved, from the minister down would have to answer to a court if deaths result during a disaster."

Stephen Conroy, Minister for Communications appears to agree with this point of view. On the ABC Insiders program yesterday, he said:

"... And to give you another example, a story was written on Saturday I think, yesterday which suggested that we were going to be not having battery back-up.,

The journalist was told the Government has instructed the national broadband network that battery back-up will be mandatory. Yet the story still appeared without any reference to that. ..."

However, the NBN Tasmania web site says that backup batteries are an optional extra:

"The NTU is supplied with a 240-volt regulated power supply. You can purchase and install a back-up battery to minimise the risk of interruption to the telephone service when there is a power failure. Once the battery is installed and charged, the NTU will remain operational for up to 4 hours in the event of a power outage. Unless a battery is installed and maintained by you or your retail service provider you will not be able to make or receive any phone calls, including calls to emergency 000 services, during a power failure."

The battery brochure from the Tasmanian NBN gives details for the customer to install the optional backup battery.

So who is correct: the Minister, or the NBN documentation?