Telstra runs hundreds of welfare checks after mobile network outage

Telstra has completed 395 welfare checks triggered by customers that could not connect to emergency services during a major mobile network outage on Wednesday.

More welfare checks may need to be carried out as well, with the telco now reporting a “secondary issue” late last night that is resulting in errors when trying to reach triple zero.

The telco’s chief financial officer Michael Ackland had initially said that triple zero calls “follow different settings in our network” to other voice and data services, which shielded them from the worst of the problems on Wednesday.

Still, Telstra had performed 395 welfare checks as of 5.30pm, which it said was unexpectedly high.

Of these, 310 callers did not need assistance. Of the remaining callers, 79 were referred to a state or territory policing agency for a physical welfare check, and six callers indicated they still required emergency assistance.

Telstra said the high number of calls requiring investigation was due to a variety of reasons. 

“In some cases, a phone wasn't able to connect correctly on its first call attempt, which triggered a callback from us,” the telco said.

“In other cases, the call was picked up by the TPG or Optus networks and connected successfully.”

The telco also said the number of welfare checks was “inflated by a larger number of people calling to test triple zero, and as a flow-on from the core issue.”

New issue with network emerges

That “flow-on” appeared to be a reference to a “secondary” issue that materialised late Wednesday, and impacted emergency calls.

“In these cases, when you call triple zero you will receive an error message and your phone will try to connect to an alternative mobile network,” Telstra said.

“As part of our back up process, we will complete a welfare check where we detect a failed triple zero call.”

Telstra said that it could take “up to 90 seconds” for an emergency call to be re-routed over another telco’s network under a process called ‘camp-on’, which is designed to prevent emergency calls from being dropped during an outage by one network operator.

Rival Optus has previously said the delay to route an emergency call over healthy mobile infrastructure near the caller can be up to a minute long, with the user greeted by silence.

Telstra indicated on Thursday morning that its teams had "made good progress reducing the occurrence of the subsequent triple zero calling error by approximately 90 percent."

"[We] will continuing work to eliminate this issue entirely," the telco said.