Top Optus executives will be grilled over the telco's disastrous handling of a deadly triple-zero outage along with the minister responsible for the network.
The Senate on Tuesday passed a joint bid by the Greens and coalition for an inquiry into the September outage that is linked to three deaths.
The minor party wants to put the "blowtorch" on Optus and the communications watchdog's relationship with the telco.
The role of Communications Minister Anika Wells in ensuring the resilience of the triple-zero network as a whole will also come under scrutiny.
Optus executives might face the probe at Parliament House as early as Monday.
The embattled telco's parent company Singtel will also be scrutinised for how it ensures Optus meets its obligations to provide a dependable service.
Opposition communications spokeswoman Melissa McIntosh said the triple-zero network needs to be examined.
"I want the whole triple-zero ecosystem to be questioned and to be tested, to be prodded, and for people to have reassurance that every part of that process, every part of the business process, contract, everything is investigated," she said.
Liberal senator Sarah Henderson, who moved the motion to set up the inquiry, called on Ms Wells to appear before the probe.
"We are determined to apply the blowtorch to Optus, the government, the minister and the regulator," Senator Henderson said on X after the motion passed.
A triple-zero custodian will be set up following the passage of legislation in the upper house on Tuesday to increase penalties for breaches to $30 million.
While the Australian Communications and Media Authority has set up its own inquiry into the deadly outage, Senator Henderson said it was "woefully inadequate and riddled with conflicts of interest".
The inquiry will investigate the regulator's response to the outage and whether more could have been done by them or the government to prevent the loss of life.
An Optus spokesperson said the company had commissioned an independent review and was co-operating with the communications watchdog.
The minister has meanwhile notified the communications watchdog of an intention to establish a public register of network outages to ensure people are aware in real time.
"Triple zero is a critical public safety system and Australians need confidence that it will be available when they need it," Ms Wells said.
