A major outage at Optus, Australia’s second largest telecommunications provider, has left millions of Aussies without mobile phone service, internet access, and vital connections for nearly 12 hours and counting.

The network disruption began around 4 AM local time on Wednesday, affecting over 10 million Optus customers across the country. The cause of the prolonged outage remains unclear, with the company still working to identify and resolve the core technical issue as of late morning in Australia.

With Optus providing service to an estimated 50% of the population, the outage has severely disrupted transportation, commerce, hospitals, and other critical services that rely on stable communications. Optus, owned by Singapore Telecommunications Limited, has faced mounting criticism over poor customer service amidst the ongoing loss of connectivity.

“We apologize to our customers and we are working hard to restore services as soon as possible,” said Optus CEO Kelly Bayer Rosmarin in a statement around 11 AM. While the company slowly began restoring some services, experts say it could be many more hours before the network is operating normally again.

Outage Leaves Aussies Unable to Access Critical Services

The Optus technical meltdown left people across Australia unable to make phone calls, access the internet, or use apps that require mobile data or WiFi. As the outage dragged on through the morning and afternoon, the impacts became increasingly disruptive for individuals and businesses.

With Optus equipment powering critical communications, hospitals lost connections to patient monitoring systems and access to electronic patient records. Doctors and nurses were forced to rely on personal mobile phones to reach specialists and transfer patients.

Public transportation was also hamstrung in multiple states. In Victoria, train network V/Line was forced to suspend all services due to the Optus outage disabling safety systems. Transport officials told commuters to avoid non-essential train trips until the issue was resolved.

Retail stores and restaurants able to open were left only able to process cash payments. Payment terminals powered by Optus were down across the board. Even businesses using reserve 4G networks were affected as the scale of the outage overwhelmed backup systems.

For individuals, the loss of connectivity meant missed medical appointments, being unable to reach loved ones, and loss of income for gig workers and small business owners.

“I’m just waiting for results for my dad’s cancer treatment, and I can’t even get those through,” said Danielle Hopwood, an Optus customer interviewed by the Australian Broadcasting Corporation.

Network Issue Traced to Fault in Optus Core Infrastructure

In a press conference and media interviews, Optus CEO Kelly Bayer Rosmarin said the company had traced the cause to a major fault deep in its network core infrastructure. Optus engineers detected no signs of a cyberattack or external breach.

“This is not a cybersecurity issue,” Ms. Bayer Rosmarin told the Sydney Morning Herald. “We have been able to confirm it is not a denial-of-service attack or a network incident.”

Minister for Communications Michelle Rowland said briefings from Optus indicated the issue originated from the domain name system, which supports internet communications by linking website names to IP addresses.

“My understanding is that this is a fault inherent deep in the core of the Optus network,” Minister Rowland stated. “It’s a fault that is quite fundamental to the network.”

As of midday in Sydney, Optus had yet to elaborate on the specific nature of the core infrastructure failure. IT experts theorized it could involve DNS servers, network switches, critical data pipes, or other backbone equipment.

Previous Data Breach Fuels Criticism Over Lax Security

The outage piles onto existing criticism of Optus over a massive data breach in September 2022. The company revealed that a cyberattack had compromised the personal data of up to 10 million customers — nearly every client on its books.

The hack exposed Australians’ driver’s licenses, passport details, email addresses, phone numbers, and more. It prompted scrutiny from regulators and accusations that Optus failed to adequately protect customer data.

“Given the recent data breach, I imagine public trust in Optus is quite low,” said Rob Nicholls, associate professor of regulation and governance at UNSW Sydney Business School. “This will be another blow and will require a lot of work to regain consumer confidence.”

Though apparently unrelated to cybersecurity, the network disruption may trigger further review of Optus systems and infrastructure safeguards. “When you have an outage of this scale, it raises legitimate questions around redundancy, resiliency, and crisis response plans,” Nicholls added.

Widespread Outage in Australia Highlights Telecom Vulnerabilities

For many Australians, the Optus debacle underscores the risks of relying on just a handful of telecom providers. Optus and Telstra control over 80% of the mobile market in Australia. Such consolidation means outages can easily cascade into nationwide disruption.

“This shows how vulnerable Australia’s telecommunications networks are to technical failures,” said Tony Hall, senior lecturer in IT services management at RMIT University. “When you have a highly centralized system, even small initial glitches can ripple into catastrophic service impacts.”

As Australians await restoration of normal Optus service, regulators and industry analysts say the event should spur investment in diversifying infrastructure and adding redundancy. Bolstering network resiliency may carry high costs, but prove well worth it to avoid future outages on this scale.