The head of the government body rolling out the National Broadband Network (NBN) has defended the current mix of technology for the rollout as being adequate for today's needs.

"I would ask everybody that, with their own taxpayer money, would you rather spend it now and bet that it's going to be needed, or wait and spend it as it's actually proven to be needed?" NBN chief executive Bill Morrow said.

"All evidence suggests what we're doing today is the right way.

"But I'm not Nostradamus.

"It's very hard to predict exactly what the consumption requirements or speed requirements will be."

Mr Morrow said fibre-to-the-node (FTTN) could be upgraded in the future if there was enough demand.

FTTN technology uses existing copper wires to connect houses to the broadband fibre, and was a key policy difference between the Coalition and Labor during the last federal election.

Mr Morrow also brushed aside claims the controversial FTTN rollout was behind schedule.

"The rollout is on track," he told 7.30.

Mr Morrow was responding to a series of leaks from NBN over the past few weeks, showing design deadlines for FTTN were not being met, partly due to negotiations with power companies.

"There are some things that we're ahead on, some things we're behind on, but it's all by design with the appropriate caveats and contingencies in place to make sure that that rollout stays on track and that's exactly the case," he said.

So far nearly 50,000 homes are using this technology to access high-speed broadband.

The Coalition argued its approach would be cheaper and deliver faster internet speeds to Australians sooner.

Mixed technology is obsolete and second hand, say critics

However, Mark Gregory from the School of Engineering at RMIT, was scathing of the rollout.

"It's probably the most expensive project to roll out an obsolete second-hand technology in the world's history," he said.

One of drawbacks of FTTN is that it's considerably slower than connecting fibre all the way to the home.

Mark Gregory from the RMIT School of Engineering, is scathing of the mixed technology approach of the NBN.

Mr Gregory said it would also cost more in the long term to upgrade if FTTN could not cope with demand or meet future speed requirements.

"To upgrade the fibre-to-the-node technology, you have to spend essentially more money than it would have cost to rollout fibre-to-the-home in the first place," he said.

The Coalition Government did not direct NBN to use FTTN technology, but rather gave it overall instructions to use technology that could be rolled out as soon as possible for the least cost to taxpayers.

NBN is now using a mix of technologies, but Mr Morrow said under those current government directions, FTTN was still the best option for connecting most Australians to broadband.

But he admitted NBN was having a serious look at a new technology that uses less copper wiring, known as fibre to the distribution point.

"Right now we're within a $400 envelope of cost (compared with FTTN)," he said.

"I would say there is already a minor shift in the technology mix because of recent developments.

"It could turn major if we continue to reduce the price and increase the speed of deploying the alternative technology."

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'Anything will be better than what we have now'

As the NBN rolls out in Gympie in south east Queensland, local video producer, Luke Soanes, said he was excited about the arrival of FTTN.

Current internet speeds in the area are excruciatingly slow, taking up to 18 hours to upload a single video.

"Anything is better than what we've got at the moment," he told 7.30.

However Mr Soanes would like the network to be even faster.

"I could do with double the speeds," he said.

Tim Jensen, the owner of a nearby milk trucking business BLU Logisitics, said the speeds promised by FTTN were good enough for now.

"I think what we're stuck with now, and what fibre-to-the-node will give us is a vast, vast improvement," he said.