Broken timers trigger nationwide Telstra outage

Time-keeping technology triggers Telstra nationwide outage. Here's what we know

The outage is believed to be linked to time synchronisation systems. (ABC News: Billy Cooper)

Telstra's chief financial officer has fronted the media, saying Wednesday's nationwide outage was caused by malfunctioning "nodes" that manage time synchronisation within some of the network data centres.

However, Australia's biggest telco says it has no idea what caused the timer issues.

The outage has affected potentially millions of Australians by impacting payment systems and public transport services.

The Telstra outage happened on Wednesday morning, with outage monitoring site Downdetector.com showing a large spike in reports beginning about 4:30am AEST.

Downdetector.com shows a huge spike in Telstra outage reports after 6am. (Supplied: Downdetector.com)

The number of reports made to the website doubled from 308 to 776 between 5:27am and 5:42am, before hitting a peak at 6:42am when more than 7,000 people lodged issues with Telstra's services.

These numbers have since fallen significantly.

Mobile signal was the most commonly reported issue (49 per cent), followed by mobile internet (42 per cent).

How many people have been affected?

Potentially millions of Australians across the country.

Telstra's chief financial officer (CFO) Michael Ackland said in a press conference that he was not sure of the exact numbers, but believed it was in the thousands.

"It could be tens of thousands, but I think it's more likely in the thousands," Mr Ackland said.

The outage was not focused on a particular state, with Telstra customers all across the country expressing their frustration.

But not all the telco's customers were affected, with some reporting on social media and to the ABC that they were still able to make calls, send text messages, access the internet, or have full access.

What caused the Telstra outage?

We don't know the root cause of the outage.

However, Mr Ackland said the issue likely involved "nodes" in Sydney and Melbourne data centres that help synchronise network systems.

The nodes serve a function by keeping time across Telstra's entire mobile network, meaning that disruption to that service is replicated throughout the system.

"You can imagine that lots of computer systems have to synchronise time," he said.

"It's one of the ways that you authenticate what's going on in the network. And the time synchronisation in those nodes wasn't working as it should. We don't know why yet."

The SOS and satellite icon appeared on Telstra phones. (ABC News)

Mr Ackland added that the telco had been able to restore some of the nodes within the affected data centre servers, but that it would take time for them to sync up with the wider network, and that there was still "further restoration to occur".

Telstra said there was no evidence of a cyberattack or malicious activity and that it would continue investigating all possible causes.

Why can't I make calls or use mobile data?

That's probably because your phone plan is with Telstra or other mobile providers that operate on Telstra's network, including Boost, Aldi, Tangerine, Belong and Everyday Mobile.

Telstra recommends trying the following steps to reconnect to the network (these may not work for everyone):

When will the Telstra outage be fixed?

We're not sure how long it will take to rectify the outage completely.

But in a statement released around 10am AEST, Telstra said it had "just under 90 per cent of calls and data now flowing successfully across the network".

"Our teams are working as quickly as possible to restore remaining services and get all customers back online," it read.

Mr Ackland said Telstra's immediate priority was to restore services, before it considered customer compensation.

"Our focus at the moment is absolutely on getting things up and running, and we will deal with our customers post the event," he said.

The implications of the outage have been widespread, affecting Triple Zero (000) calls, regional train services and payment systems.

State police services reported that while the Triple Zero call centres were unaffected, some Telstra customers attempting to call them were.

The telco said it was conducting welfare checks on customers it was aware of who couldn't make emergency calls.

"We don't believe this issue has impacted Triple Zero in the same way as other calls," Mr Ackland said.

"But we are continuing to investigate every angle on where it may have impacted Triple Zero, if that has occurred."

He asked people not to test the line unless they needed it.

Communications Minister Anika Wells confirmed that some emergency calls did not connect this morning.

This is part of Wells's statement:

"The core Triple Zero system remains operational, with connected calls flowing as expected from carrier networks to the Emergency Call Person (ECP), and on to state and territory emergency services dispatchers.

"However, the Triple Zero Custodian has advised that some callers were unable to connect to the ECP, and that these are being investigated by Telstra."

Commuters in three states have been impacted by the outage.

Victoria's entire regional passenger rail network is at a standstill.

V/Line said all its services had stopped after a radio network fault. Services on the Bendigo, Seymour, Gippsland, Geelong and Ballarat lines were suspended on Wednesday morning.

While communication with the trains has been restored since, CEO William Tieppo said trains would not be moving just yet.

"We are still seeing instability in that network, and until we get a really stable network, we're not willing to take the risk and run trains until that network is fully stable," Mr Tieppo said.

Regional and some intercity trains in NSW also face significant delays.

Transport for NSW said that train routes between Sydney and Brisbane, Armidale, Casino and Grafton were affected. It also reported train services were replaced by buses between Newcastle and Maitland, and between Campbelltown and Moss Vale/Goulburn.

In South Australia, traffic lights were also impacted. No lights were out completely, but the Traffic Management Centre is unable to intervene and turn lights green when traffic builds up at busy intersections.

Payments app Tyro was affected, the company confirmed.

Approximately 80,000 businesses use EFTPOS terminals that operate on the Tyro system.

"We're aware of an issue with a national telephone network provider and that some customers may not be able to connect to the 4G network right now to process EFTPOS transactions," it said in a statement.

"As an interim solution, until service is restored, please try connecting to your ethernet or wi-fi network."

The Commonwealth Bank of Australia said its merchant EFTPOS terminals were also impacted, and suggested customers switch connections to an Optus network or local wi-fi source.

The outage has also led to delays in Hobart's magistrates court.

ABC News journalist Sophie Jaggers said lawyers told the court this morning that they have been unable to contact their clients to remind them of their court appearances due to the outage.

So far, two cases have had to be stood down due to these communication issues.