Bizarre ‘time travel’ bug blamed for catastrophic Telstra outage

A 20-year “time travel” glitch triggered by a botched firmware upgrade is the likely culprit behind Telstra’s catastrophic nationwide mobile network outage, internal sources have revealed.

Two internal Telstra sources said the outage was caused by a software bug linked to the network’s timekeeping systems.

According to the sources, a faulty firmware update caused some of Telstra’s timing servers to incorrectly reset their clocks by 1024 weeks, or almost 20 years, making them believe the date was November 2006 instead of July 2026.

Modern mobile networks rely on highly accurate timing to authenticate devices and maintain connections. The incorrect date caused parts of the network to reject customers’ phones, leading to intermittent call and data outages across the country.

“There was an update… and it did impact what’s known as the GPS node, which caused the time to re-sync,” Telstra’s chief financial officer Michael Ackland confirmed on Wednesday afternoon. “We’re working through the details of that now.”

At about 4.30am AEST, Telstra noticed that two “nodes” that keep time synchronised across the mobile network – which is crucial for computers to work together – had stopped working as they should, causing intermittent call and data failures across the country.

The telco’s chief financial officer, Michael Ackland, said the affected nodes were housed in Telstra data centres in Melbourne and Sydney, and there was nothing to indicate malicious activity, despite suggestions from One Nation that a foreign power could be involved.

Ackland said the issues had been fully resolved by 4pm.

Wibowo Hardjawana, a senior lecturer in electrical engineering at the University of Sydney, said a node was made up of software functions that had to keep to the same clock for the network to work. “These functions must be synchronised in time and work together to enable customers to establish communication with each other,” he said.

The Communication Workers Union national secretary, Shane Murphy, called the outage “utterly shameful” and claimed it was a direct result of the company cutting staff.

“This is what happens when you prioritise the bottom line over critical services; you get an unreliable network that lets Australians down time and time again,” Murphy said. He did not present evidence to support his claim that the job cuts were tied to the outage.

Telstra has been cutting jobs and shifting work offshore under its “Connected Future 30″ strategy. In February, it proposed cutting up to 400 enterprise and consumer roles, many to be outsourced to the Indian technology firm Infosys, on top of about 209 jobs going from an artificial-intelligence joint venture with Accenture and 550 roles cut in July last year.

Telstra has not linked the outage to staffing levels, and Ackland said the cause remained under investigation. The company was contacted for further comment.

Ackland claimed about 90 per cent of calls and data services were working again by late morning, but could not say what had caused the fault, when full service would return, how many customers were affected and whether everyone whose calls to Triple Zero had failed were safe. Ackland would not commit to compensating customers who had been affected.

“Our focus at the moment is absolutely on getting things up and running and we will deal with our customers post the event, as we will work with government and regulators on any other action,” Ackland said. He fronted the media for a short press conference on Wednesday in place of chief executive Vicki Brady, who was on holidays overseas but is now returning to Australia.

The outage also brought down Victoria’s entire regional passenger rail network, while in New South Wales some regional and intercity trains were also delayed.

Prime Minister Anthony Albanese called the outage “deeply concerning” and “very disruptive” and said none of it was acceptable. He said the government was working closely with Telstra and agreed there was no evidence of malicious activity.

Emergency Management Minister Kristy McBain said she had asked the National Emergency Management Agency to convene a national coordination meeting on Wednesday afternoon, bringing together federal, state and territory agencies and Telstra.

The outage also sparked a political row over emergency calls. McBain accused the opposition’s communications spokeswoman, Sarah Henderson, of making test calls to Triple Zero during the outage, calling it “absolutely outrageous” when the network needed to be kept clear for people in genuine emergencies.

Greens communications spokesperson Sarah Hanson-Young said her party would seek to amend telco laws when parliament resumed in August. She said the government had failed to deliver necessary reforms since the Optus outage last year and claimed that the Australian Communications and Media Authority was too “cosy” with the telcos it regulates.

Australia’s telcos have been under sustained scrutiny over reliability since two Optus failures. A nationwide Optus outage in November 2023 knocked out more than 10 million services and left about 2000 people unable to reach Triple Zero, and a separate Optus outage in September last year, in which hundreds could not reach the emergency line, was linked to two deaths and led to powers for a Triple Zero custodian and tougher rules now being tested by Wednesday’s failure.

The Optus outage was caused by a late-night upgrade to firewall software by outsourced contractors that went awry and was not picked up properly for hours.

Nearly a year after the fatal Optus outage prompted the overhaul, parts of it remain unfinished. The government says almost all the Bean review’s 18 recommendations have been implemented, but the last and largest, a full review of the laws underpinning Triple Zero led by the custodian, is not due to report until March 2027. The regulator is separately still investigating the 2025 Optus outage.

Other providers who rely on Telstra’s wholesale mobile network were affected, including mobile virtual network operators such as Boost Mobile, Belong, Aldi Mobile and Tangerine Telecom. Payment systems were also caught up.

The Australian Communications Consumer Action Network, the peak body for communications consumers, said the outage showed Australia still had no enforceable reliability standards to hold carriers to account for network stability. Its chief executive, Carol Bennett, said Telstra needed to explain “what has happened, who is affected, and when services will be restored”.

Telstra ruled out a trading halt over the outage, with Ackland telling reporters the company was not going into one. Its shares were trading a little under $5 at 2.40pm AEST, down 2.4 per cent.

The telco provided about 24.9 million retail mobile services as of June last year, according to the company’s most recent figures. It was fined more than $3 million in 2024 over an earlier outage that stopped some customers reaching Triple Zero.

with Jack Gramenz

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