The country's biggest telco said in a statement that this upgrade was part of its T22 plan which was announced in June last year.
Chris Meissner, Telstra’s Transport IP Core and Edge Engineering executive, said the upgrade had been done as part of the Networks of the Future program which called for building the next-generation Optical Transmission Network.
"This was no simple exercise, given not only the size and complexity of our network, but also the challenges we face in Australia when it comes to the enormous distance between cities, and unique environmental factors in building next generation technology throughout some of the most remote and hottest regions of Australia," Meissner said in a statement.
Under the T22 strategy, Telstra said it would effect a net reduction of 8000 employees and contractors by 2022 and reduce two to four layers of management, leading to the cutting of one in four executive and middle management roles.
The company has also reduced the number of mobile plans it offers, simplifying them down to about 20.
Meissner said: "With the meshed nature of the new optical network, we are able to quickly reconfigure the network to stand up new routing paths within hours to reduce the overall risk of faults - this is something that previously would have taken days. In the future, we will be able to reconfigure the network within minutes in the event of a service disruption, providing our customers unprecedented connectivity.
"Our new optical transport network will also see the introduction of software defined network orchestration, which will enable the fast turn-up of optic wave services for our enterprise customers through the digital stack. Where we have the infrastructure in place, customers will be able to activate new services within hours rather than days or weeks."
The NBN was supposed to lay fibre-to-the-home for 93% of the Australian populace, which would have enabled these residences to get gigabit connections. But the plan was changed in 2013 and as things stand, only some suburbs on the mainland and a large part of Tasmania have FttH.