Mark Gregory, associate professor in network engineering at RMIT, told iTWire that Morrow now appeared to be looking for a parachute.

Morrow, who is on a 457 visa, will need to have it renewed next year if he is to continue heading the troubled public sector company.

Gregory added that while the Coalition Government representatives seemed to be indicating on the programme that everything was hunky-dory, Prime Minister Malcolm Turnbull himself was now admitting that Australia should have followed the New Zealand model.

Communications Minister Mitch Fifield, who appeared on the programme, referred to the network as being "fit for purpose", but also said that nothing was set in stone and things needed to change as and when technology dictated it.

Gregory was of the opinion that the New Zealand path should be taken as soon as possible. He said that by adopting fibre-to-the-node technology, the government had caused the issues that it was now facing.

He said it was possible to make the switch now and avoid a bigger mess than what existed at the moment.

Robin Eckermann, an adjunct professor at Canberra University, said he had watched the Four Corners programme "with a mixture of interest, bemusement and dismay at various inaccuracies in the story as portrayed".

"There was an excessive focus on the different access technologies that NBN Co is using and insufficient focus on the biggest problem that afflicts the network right now - that is, the performance degradation that results from overloaded CVC capacity," said Eckermann, the chief architect behind the TransACT network.

He said some of those with fibre connections who appeared on the programme also complained of poor speed during busy times. "So right now, more fibre connections wouldn't address the 'elephant in the room' problem that's dragging performance down. Unlocking more speed in the final few kilometres of dedicated cabling to the premises is going to be irrelevant if all the connections at 12/25/50/100 Mbps are channelled into a shared pipe (ie: the CVC) where an average capacity of just over 1 Mbps per user is currently being provisioned," he pointed out.

Eckermann said the issue got only a brief mention, but several spokespeople had dismissed the problem by saying it was the RSPs' fault for not buying enough capacity. "In my view, that is evading the real issue - most Australians work within affordability limits and simply do not have the capacity to a whole lot more for fixed broadband."

New access networks did not have a good track record of delivering promised returns on investment. "Witness the Optus and Telstra HFC networks, and TransACT's network here in Canberra where investors had to accept a significant write-down in the capital value of the network when it was sold," he said.

"While the government clings to the illusion that the NBN will deliver a return on investment, CVC capacity will be priced at a level that leads to performance being throttled - and this risks making the entire expensive investment a failure in terms of equipping Australia to optimise its digital future.

"Ultimately the way to fix the problem is for the government to accept that the target return is not achievable - and by resetting the expectations, allow CVC pricing to fall to sensible levels (or zero!) and thereby unlock the full transformative potential of the network. In my view, it is only a matter of time before this becomes bleedingly obvious - but until that happens, the performance problems will continue to fester."