Telstra (ASX:TLS) Chief Executive Vicky Brady on Friday confirmed that last week's triple zero outage may not have occurred if appropriate technical updates and maintenance documentation had been completed.

Telstra Executives appeared before the Senate Environment and Communications References Committee to answer questions about a network outage that left millions of Australians disconnected from emergency services.

Brady said that a server in Melbourne went through an undocumented design change, and later, a hardware replacement caused the outage, as the officials were not aware of the design change.

"Had that software update been completed, or had the design change been properly documented and reflected in the maintenance procedures, the outage may not have occurred," said Brady.

Telstra faced sharp questions and scrutiny from the senators as the company had received a reminder in January, as well as a warning in 2022, for the key software update, which it failed to perform.

"If you don't even have the documentation, how are we to believe that this couldn't just happen again?" asked Senator Sarah Hanson-Young.

Brady said that the company has paid out about AU$100,000 in compensation to users so far and has received over 8,000 claims, but said these are "very, very early days" of the payouts.

Bill Gallagher, the company's risk executive, said other participants in the Triple Zero ecosystem should have their risk management plans in place to avoid similar outages.