Telstra, as holder of the federal government’s emergency call provider contract, has told a parliamentary inquiry into the fatal September Optus triple zero outage that it did not detect the disruption on the day it occurred.
Furthermore, it said it found “no evidence or missed or failed emergency calls” and that all its systems operated normally during the incident.
Instead, the telco said, it first became aware of the incident when Optus held a televised media conference on the incident.
As the Emergency Call Person (ECP) – the formal name given to it as the emergency call provider contract holder – the carrier is the first point of contact for emergency calls, including other providers.
Telstra said that the only hints it received that Optus might have been experiencing triple zero calling problems involved brief text messages, a phone call and an email, some of which at times appeared to contain contradictory information.
At around 2.20pm on September 18, two short text messages arrived a second apart. In the first Optus warned that it had an identified an issue with triple zero calls in South Australia and West Australia, “possibly since 3am today” and that it was “commencing welfare checks”.
One second later, another message arrived: “Issue now resolved by rolling back a network change. It appears only ~10 (triple zero calls) impacted. We’ve notified ACMA (the Australian Communication and Media Authority), SAPOL (South Australia Police) and WAPOL (Western Australia Police) as well.”
Optus called Telstra’s Triple Zero Incident Operations team at 3.17pm on September 18 advising they had an issue and would follow up by email.
The team told Optus that the email hadn’t arrived. It was then discovered that, although Optus had attempted to use the right address, a small typographic error meant that it had be forwarded to Telstra again using the correct one.
The forwarded original email was timestamped about eight minutes earlier but, in it, Optus merely advised that it was aware of a “significant outage” affecting emergency calls on its network.
The email’s footer contained an incident number followed by what appeared to be a machine-generated strip of text indicating that the incident had been resolved 2.34pm AEST 19/09/2025, a whole day in the future, and brief description of the incident:
Mobile users unable to dial Emergency from South Australia, Western Australia. A short time later Optus sent another email correcting the date.
Telstra included a timeline of events in its submission to the inquiry which was made public today along with those of TPG Telecom and the NSW Telco Authority.
As reported by iTnews, the Department of Communications, Singtel and the Australian Consumer Communications Action Network were published on the parliamentary inquiry website late yesterday.
In its submission, Telstra also told the committee inquiry that it detected no other unusual signs from its emergency call monitoring systems that anything was amiss.
“During the September 18 2025 incident, the ECP’s, and Telstra’s, systems operated as intended, with no evidence of missed or failed emergency calls at the ECP or within our network.
“Once we were advised of an issue in Optus’ network, the ECP’s monitoring and welfare check processes were activated, and we maintained close communication with emergency service organisations (ESOs) and government stakeholders throughout the event,” the carrier wrote in its submission.
It also detected no unusual changes in emergency call volumes when compared against daily averages calculated from annual calls.
“In FY25, the ECP answered around 11.7 million calls, which is an average of 32,000 per day. Due to the volume of calls impacted by the Optus Incident and the time of day, the variation in call volumes was within the range of normal traffic variations that occur every day,” the carrier said.
Similarly, it detected no “abnormal” activity indicating that mobile handsets were attempting to camp on to other networks to get around calling problems with their home networks.
Camp on is process when mobile handsets attempt to connect to an alternative network when their users’ home network goes dark or is out of reach.
“Optus’ submission notes that 66 of the 605 unique service numbers were able to camp-on to another network. Across all the camp-on and normal calls, a rise of 66 calls across WA, SA and NT (Northern Territory) over a 14-hour period is not discernible. As such, there were no abnormal patterns to alert us ahead of Optus contacting us,” Telstra said.
Nor was there a discernible drop in emergency calls from Optus network, its performance dashboards visualising nothing unusual.
It contacted state and federal government stakeholders on the Friday after the incident to advise them that there were no issues with its triple zero platform.
The inquiry is expected to hold another hearing into the outage next this month.