Telstra has attributed a widespread network outage to a combination of a missing software update and an undocumented design change. The company revealed in a submission to a Senate inquiry that a network time protocol (NTP) server in Melbourne, responsible for ensuring systems had the correct time, inadvertently reset to the year 2006 during maintenance.
This incorrect date then propagated across Telstra's network over several hours, causing security and authentication systems to fail as their certificates became invalid. This resulted in intermittent 'no service' issues for customers, affecting their ability to make calls and use data. Telstra acknowledged that an intentional design change made to the equipment to fix a prior fault had not been properly documented, meaning maintenance staff were unaware of its specific reset behavior. The company stated that if the pending software update had been applied, the outage might have been averted.
Telstra asserted that the issue was not a lack of hardware redundancy or network architecture flaws, but rather the acceptance of erroneous date information by interconnected systems. The company took full accountability for the incident, admitting that its controls were insufficient if maintenance work could trigger such a significant disruption. During the outage, Telstra reported that 58,835 calls to the emergency triple zero service connected successfully, while 604 experienced errors. The triple-zero platform itself was unaffected as it does not use the affected NTP servers for synchronization, nor were fixed-line NBN callers impacted.
Chief Executive Vicki Brady and other executives are scheduled to appear before a Senate inquiry, initially established for last year's Optus outage, to provide further explanation. The inquiry aims to uncover the full details of the incident and ensure measures are in place to prevent future vulnerabilities.