Telstra CEO Vicki Brady came back from leave on July 9 as the company faced a nationwide network outage.
The failure blocked Triple Zero emergency calls and crippled transport systems.
Brady offered a public apology and said investigations are in progress to find the cause.
The outage has triggered transport delays throughout the nation.
Media and regulators are observing her response and upcoming steps.
The incident set off a cascade of failures in Telstra’s core network, bringing about loss of voice and data services for millions of customers.
Emergency responders cited trouble reaching callers.
Government officials called for a full report.
Brady promised to reinforce systems and rebuild trust.