The parent firm of Australian telecoms company Optus said on Thursday that a software upgrade was “not the root cause” of a massive outage that affected more than 10 million customers last week.
Australia’s government has launched an investigation into the nationwide outage that crashed electronic payments, disrupted phone lines used by emergency services, and stopped people from accessing government systems for almost 12 hours last Wednesday.
Optus apologised in a statement on its website and said the outage was caused by network changes to routing information following a software upgrade.
Its Singapore-based parent firm Singtel said on Thursday that the network had conducted a routine software upgrade on one of its routers last Wednesday.
“We are aware that Optus experienced a network outage after the upgrade when a significant increase in addresses being propagated through their network triggered preset failsafes,” Singtel said in a filing with the Singapore Exchange.
“However, the upgrade was not the root cause.”
Optus had said the routing changes “propagated through multiple layers in our network and exceeded preset safety levels on key routers” and “resulted in those routers disconnecting… to protect themselves.”
Optus is Australia’s second-largest phone provider with more than 10 million customers.
It was hit by a cyberattack last year that compromised the personal data of over nine million customers.
The company is a wholly owned subsidiary of Singtel, which has expanded beyond the domestic market to establish a presence in Asia, Australia and Africa. — Agence France-Presse