Backup failed in Telstra's triple-zero outage

Telstra CEO Vicky Brady says Telstra has put measures in place to prevent a repeat of a triple-zero system outage it experienced late last week, while it continues to investigate the root cause of the problem.

The 90-minute triple-zero outage last Friday, from 3.30am to 5am, meant 148 of the 494 calls received during the outage could not be transferred to state emergency services organisations.

During that time, one man died in Victoria during a cardiac arrest.

Yesterday, the ACMA began investigating Telstra’s regulatory compliance over the outage.

“Calls were coming through to our call centre, but they didn’t have calling line identification or CLI”, Brady said.

CLI allows Telstra to switch the call to the right state, and pass location information to emergency services along with the call.

“We immediately moved to our backup processes, which meant that our people needed to ask the caller where they were located, and then they tried to manually transfer that call on to emergency services.”

In 148 cases, the call transfer didn’t work, and Telstra was forced to transfer information via emails, some of which took hours to arrive.

The system that provides the CLI information, Brady said, “became overwhelmed”, for reasons that are now a focus of Telstra’s investigation.

To compound the problem, “the backup system didn’t work as intended," Brady said. “I know it didn’t fail over to its redundant server”.

In response, Brady said that Telstra has "taken immediate actions".

"We’ve put in place heightened monitoring, we’ve got extra resources in place, we’ve put in place some additional measures to make sure this platform is stable, and we’ve made some changes to make sure all those backup processes are also working.”