Disaster waiting to happen: One of the biggest concerns of the agencies whose job is to safeguard the internet is cyber-terrorism. Photo: iStock

It was 5.30am on November 22, 2012 when Greg Walsh had his first inkling that the internet had stopped working. As a farm manager near Warrnambool, he had risen early to check his email and send instructions to the farm managers he oversaw.

Except on this morning, his home connection to the internet wasn't working. That was not entirely unheard of but he discovered his mobile phone connection was also down. So too was his home phone.

There is the much bigger question of whether the global economy could survive losing the internet. 

It took a much older form of communication - radio - to learn that a fire had damaged the Telstra exchange. The mystery was solved but its ramifications were only just becoming clear.

Keen to get on with his day, Walsh started the 20-minute drive to town.

"I got halfway and realised I was almost out of petrol," Walsh says. "I pulled in to the nearest service station only to find that the payment service was down, and that I needed cash to buy petrol. And I had about $5 in my pocket."

When he finally made it into Warrnambool he found the ATMs there weren't working either. So he joined the long queue outside a bank where tellers were handing $100 to anyone who could prove their identity and recording the transactions on paper.

"That was the first realisation that this was something wider than just day-to-day communication," Walsh says. "It was a shock to realise just how widespread the ramifications were."

It took Telstra nearly three weeks to get the Warrnambool district fully back online. While mobile and some emergency telephone services were back within days, internet services took longer. During that time businesses lost thousands of dollars through being cut off from their systems and customers. To date Telstra has paid out up to $1000 to nearly 2000 businesses, and is assessing a smaller number of larger claims.

That a small fire could have such consequences is testimony to how deeply the internet has become woven into our society. It's even more remarkable because most Australians have been using it for fewer than 15 years.

As the people of Warrnambool learnt, it wasn't only email and web access that they had lost. The fire also took down their ability to conduct business and communicate with the rest of the digitally enabled world. For the better part of three weeks they disappeared into a digital black hole.

The Warrnambool incident was limited in scope but would it be possible to take down the entire internet? With business and society dependent on it, there is growing concern about whether the internet can survive attacks or other catastrophes.

"I think we'd have a global crisis of terrible proportions," says Rod Tucker, director of the institute for a broadband-enabled society at the University of Melbourne.

"It is conceivable that you'd have a major global crisis with civil unrest within weeks. Business is now adapted to the situation where everything happens via data and you don't need the telephone - and if we had to fall back to the telephone it couldn't cope with the way we do business today."

So it's good to know that a number of agencies, including the CSIRO and the intelligence organisation Defence Signals Directorate in Canberra are working to safeguard the internet.

One of their biggest concerns is cyber-terrorism, particularly when directed by nations.

In 2008, the former Soviet republic of Georgia accused Russia of a co-ordinated attack on Georgian websites as part of an offensive against South Ossetia. In effect the attack took Georgia off the internet.

According to the director of digital productivity and services at the CSIRO, Ian Oppermann, one of the greatest survival attributes of the web is inherent in its name - it is a web of connections designed to survive the loss of even a large number of individual points. The web's design means data is simply rerouted around problem areas.

"So it would be a pretty catastrophic set of events that would potentially do something to bring the web down."

One possible way to take down the internet is a concerted attack against the so-called top-level domain servers that send traffic to websites.

Hackers also take websites offline by directing massive volumes of junk traffic to them. But these are usually isolated to individual companies and organisations.

Natural dangers also exist. Oppermann says that on occasion North America has had problems with its interstate power line networks thanks to the effects of solar flares. Satellites are also vulnerable to this form of natural attack.

It is also possible to disrupt the physical connections that link the internet. According to the Asia-Pacific director of online security company Sophos, Rob Forsyth, problems would quickly emerge should anyone damage the five undersea cables that carry much of Australia's internet traffic.

"Australia does have satellite connections in addition to the undersea cables but satellites can be slow and expensive to move large amounts of data," Forsyth says. "Realistically though, even losing several of these connections is unlikely to wipe out the network on a global level."

As a vice-president for technology maker Cisco, Robert Pepper works with governments to better understand the internet's impact on society.

"We expect it to be there. Our lives are built around it. And having experienced it, if you had to go cold turkey, it would be a real shock.

Some changes would be fairly frivolous, such as the loss of online shopping. But the same network delivers life-saving information to medical professionals. Loss of the internet could truly have life or death consequences.

In Warrnambool, Walsh's first experience was the loss of email. But the impact was much greater for businesses that traded over the internet.

Warrnambool businessman Robert Lane says travellers were turning up to hotels after booking online only to find the staff had no record of their booking. Online retailers could not take orders; banks and merchants could not process electronic transactions, and online banking was unavailable.

But Lane says it wasn't all bad - at least initially. "For the vast majority of people, once they got over the initial panic, the overwhelming feeling was 'isn't it great - we'll have to get in the car and visit people'.

But Lane's business - the local arm of a business consulting firm - soon suffered. His colleagues are scattered around Victoria.

''Being able to manage, to get access to information, was quite difficult … we had to go and physically visit people." Which is not so easy when your clients and colleagues are hundreds of kilometres away.

The changes that the internet has wrought on Australian society are staggering, as is our willingness to embrace it. We have flocked to internet banking, and in travel, internet bookings now account for 40 per cent of overall bookings, according to PhoCusWright market research.

And without the internet, there would be many more lonely people. According to online dating service RSVP - owned by Fairfax Media - 8 per cent of Australians met their present or most recent partner online.

Then there is the impact on younger people who have never lived without the internet. More than 10 million Australians use Facebook to keep in touch with friends and family, share photos and organise events.

And there is the much bigger question of whether the global economy could survive losing the internet. Companies including Google, Amazon and eBay rely on it for their existence, and their values would plummet should the internet cease to function. Companies such as Hewlett-Packard, IBM and Apple would struggle to survive.

Whether the global financial markets could absorb the collapse of so many big companies without going into a tailspin and taking the global economy with them is doubtful. And without the internet and similar dedicated financial services networks it would be almost impossible to trade stock anyway. The world would lose the economic stimulus and productivity boost that the internet has provided. According to McKinsey & Company the internet has created 2.6 jobs for each job lost to technology-related efficiencies.

A study by Google and Deloitte Access Economics released in August 2011 found that 3.6 per cent of Australia's gross domestic product was a direct contribution by the internet, and delivered $50 billion in value. Also, 190,000 people were employed in occupations directly related to the internet. Were the internet to stop, these jobs would be lost immediately.

In Warrnambool Telstra continues to assess claims from business customers. The outage has left many of them asking how they can avoid a recurrence and how they might make themselves less dependent on the internet.