Optus reveals cause of massive network outage which crippled nation

The cause of the nationwide outage at one of Australia’s biggest telco companies, that crippled everything from phone reception to train networks, has been revealed.

Optus has revealed the cause of an outage that crippled the nation, leaving millions of customers without phone or internet reception and affecting thousands of businesses.

Last Wednesday’s nationwide outage has been blamed on changes to “routing information” following a software upgrade at the telco.

“At around 4.05am Wednesday morning, the Optus network received changes to routing information from an international peering network following a routine software upgrade,” Optus said in a statement on Monday.

A change for ‘routing information’ has been blamed for Wednesday’s 13.5 hour Optus outage. Picture: NCA NewsWire/ Martin Ollman

“There routing information changes propagated through multiple layers in our network and exceeded preset safety levels on key routers which could not handle these.

The statement said the action resulted in routers disconnecting from the Optus IP Core network to protect themselves.

This resulted in a large scale effort to reconnect or reboot the routers physically, requiring “the dispatch of people across a number of sites in Australia”.

“This is why restoration was progressive over the afternoon,” Optus said.

The explanation comes after an estimated 10.2 million customers were left without internet or mobile access last Wednesday for about 13.5 hours.

Services went down at about 4.05am, and weren’t fully restored until 5.35pm.

“We apologise sincerely for letting our customers down and the inconvenience it caused,” an Optus spokesman said.

The telco giant earlier announced eligible postpaid customers will get 200GB of extra data from Monday.

Eligible prepaid customers will be able to access unlimited data on weekends until the end of 2023.

Calls for compensation have echoed across the nation after millions of Optus customers were left without mobile or phone reception for hours last Wednesday. Photo by: NCA Newswire /Gaye Gerard

It follows widespread calls for compensation, with the federal Greens referring the chaotic outage to a Senate inquiry.

The inquiry, to be chaired by the Greens communication spokeswoman Sarah Hanson-Young, will compel major Optus bosses to publicly answer questions about the incident.

“The lives and livelihoods of millions were acutely disrupted on November 8; phones were dead, the internet down, banking broken, childcare centres closed, schools impacted,” she said.

“We want those affected to be fairly compensated and to work so this doesn’t happen again. The inquiry will look at what responsibility Optus has to protect the public, not just their profits.

“Optus is a big corporation with too much market power. The people who have been ripped off and let down deserve better.”

Originally published as Optus reveals cause of massive network outage which crippled nation