A poorly handled node used to manage voice and data traffic has been blamed for causing Telstra outages that left some users unable to use the internet or their phones across the country.
Tuesday's outage -- which affected customers nationally -- occurred after one of the nodes used to manage voice and data traffic between devices and the network started to malfunction, and the individual responsible for managing it reconnected customers to the malfunctioning node instead of one of nine spares, a Telstra spokeswoman said.
"Unfortunately, this had a flow-on consequence and it led to massive congestion across the rest of the nodes," she told channel Nine.
"I can now happily say we have restored services to all of our customers.
"Absolutely apologise right across our customer base. This is an embarrassing human error. It is not OK."
The outage is understood to have affected prepaid mobile phone customers, as well as its 4G and 3G networks.
Telstra's outage site shows the interruptions affecting customers.
The spokeswoman said there will be an investigation and Telstra is working to figure out ways to provide free data to customers to make up for the inconvenience, the spokeswoman said.
Customers and observers took to social media on Tuesday to vent their frustrations.
Attempts to contact Telstra by phone during the day were unsuccessful.