This morning Optus’s chief executive Kelly Bayer Rosmarin faced a grilling about the telco’s unprecedented network outage which saw millions of customers without access to phone and internet services.

Here’s a look at what she had to say.

More than 200 calls to triple-0 failed during the outage

After widespread reports that some mobile customers could not call emergency services during the outage, Optus’s boss has confirmed it.

“There were 228 triple-0 calls that were unable to go through, and we have done welfare checks on all of those 228 calls,” Ms Bayer Rosmarin said.

“Thankfully, everybody is OK.”

Ms Bayer Rosmarin said Optus’s technical teams were still investigating why some triple-0 calls failed, because they should have worked despite the outage.

“We don’t run the triple-0 system, we participate in the triple-0 system,” she said.

“The triple-0 system is meant to be able to pick up the traffic when we have an outage like this.”

Senator Sarah Hanson-Young, who is chairing the inquiry, accused Ms Bayer Rosmarin of “wanting to share the blame around”.

However, the CEO insisted “the-triple 0 system itself should have helped our customers during the outage”.

Thousands of customers are in compensation talks

Ms Bayer Rosmarin said so far 8,500 customers and small businesses had reached out to Optus to ask for compensation.

She said $36,000 had already been “applied” to customers, and about $430,000 was also under discussion.

When asked whether this had been paid as cash refunds or given as in-kind services, the chief executive said she did not know the details and took the question on notice.

Ms Bayer Rosmarin also said she had no details on the “veracity of the claims” or the specifics.

“I don’t want to make any commitments on what we’re going to pay,” she said.

However, she indicated that Optus was reluctant to pay out compensation for losses more broadly because it would have “far reaching” consequences for the entire telco industry and other service providers.

“There is no precedent for telcos or other essential providers covering consequential loss,” she said.

“We would welcome being part of that conversation, but don’t see it as our place to lead that.”

Resignation rumours? Optus’s CEO says she hasn’t heard them

Early this morning, there were reports that Kelly Bayer Rosmarin was considering resigning from Optus “as early as next week”.

When asked whether the reports were true, Ms Bayer Rosmarin said she was too busy responding to the outage to have considered it.

“It has not been a time to be thinking about myself,” she said.

“So that report is not correct?” Senator Sarah Henderson asked.

“I haven’t seen any reports today, I’ve been preparing for being here,” Ms Bayer Rosmarin replied.

CEO says reports blaming Singtel were a misunderstanding

Optus’s parent company Singtel was dragged into the outage saga earlier this week, when a statement explaining the cause of the catastrophe appeared to point the finger at the company’s exchange service, STiX.

Singtel issued its own statement overnight, saying multiple telcos use STiX’s international networks to connect to the global internet.

“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 fail-safes,” SingTel said.

“However, the upgrade was not the root cause.”

When grilled about this, Ms Bayer Rosmarin said Singtel and Optus were working together, and that any reports blaming the Singaporean company for the outage were based on a misunderstanding.

“[The root cause of the issue] was that Cisco routers hit a failsafe mechanism, which meant that each one of them independently shut down. That was triggered by the upgrade on the Singtel international peering network,” she said.

“That was misinterpreted by media as the root cause being the Singtel upgrade. But the trigger was the Singtel upgrade, and the root cause was the routers.”

Got that?

The ABC has contacted Cisco for comment.

Cyber attack was a genuine worry for six hours

It took Optus technicians several hours last Wednesday morning to understand what was causing the outage and how to fix it, the inquiry heard.

One of the key lines of investigation was whether the outage was caused by “malicious” activity.

Ms Bayer Rosmarin said there were some “strange coincidences” that made executives worry it could have been a cyber attack.

“For example, when we had the cyber incident [hack in 2022], was the last time the Singtel board was in town — and they were in town again,” she said.

Optus’s director of networks Lambo Kanagaratnam said the possibility of the outage being caused by a cyber attack was ruled out by 10:20am.

During the hearing, Optus’s leadership revealed the telco deals with “millions of cyber attacks” every year.

“It’s an ongoing threat and issue that we have to deal with all the time,” Mr Kanagaratnam said.