Telstra's Friday outage of ADSL and National Broadband Network (NBN) connections were due to a "complex" network management device fault, while Sunday's mobile data incident was caused by faulty hardware.
"Following disruption to some NBN voice and data services and ADSL services today, all services were restored just before 7pm EST this evening," a Telstra spokesperson said in a statement on Friday night.
"The issue we identified is extremely complex, but in simple terms, there was a fault with the device that manages the interaction between our network and all of the different types of customer modems."
The spokesperson added that Telstra will be providing more data as compensation.
"We understand this has been frustrating for affected customers, and we will be providing them with some additional data.
"We will contact them directly and provide more details."
The incident on Friday was prevalent throughout New South Wales, Queensland, Western Australia, the Northern Territory, and South Australia, with the telecommunications provider saying that a "significant restoration" of services had occurred by 11am AEST.
"Customers with NBN voice and data services and ADSL services may be having difficulty connecting to the internet," a Telstra spokesperson said at the time.
"The issue commenced early this morning, and is impacting NBN-based services and a small number of ADSL services. Services are in the process of being restored."
On Sunday, some customers again complained of losing mobile data services thanks to a hardware fault. ZDNet understands that it was an intermittent issue affecting 3G services and some 4G services mainly in NSW, although several customers across Melbourne, Brisbane, and Perth were also affected.
"Some mobile customers may have experienced a brief interruption to their data services [Sunday] morning," a Telstra spokesperson said.
"The issue affected customers in NSW mainly, as well as some other states.
"The issue was caused by faulty hardware, which has been isolated. All services have been restored."
Services were restored within two hours.
Australia's incumbent telco has had a rough start to 2016, with customers subjected to three outages over a period of six weeks: The first on February 22, which affected prepaid and post-paid mobile services and was caused by "embarrassing human error"; the second on March 17, which involved an hours-long national mobile data and voice outage; and the third on March 22, which was a smaller voice outage.
Telstra has since committed to spending an additional AU$50 million on improving the monitoring and recovery times of its network.
Telstra CEO Andrew Penn, speaking to the American Chamber of Commerce (AMCHAM) in Melbourne on Thursday, provided an updare on the telco's outages, saying the network has come out on top in terms of resilience.
"This year, we are working towards achieving peak network speeds of 1 gigabit in the Melbourne, Sydney, and Brisbane CBDs, and we will launch voice over Wi-Fi and video over LTE," Penn said.
"It is because of this commitment to network leadership that we were so disappointed with the network service interruptions earlier this year.
"We responded by conducting a full review with global experts in the field of telecommunications networks. This review, which looked at every aspect of our network, has been completed and the good news is it has confirmed the incredible strength and resilience of our network.
"While no network operator in the world can guarantee that disruptions will not occur from time to time, what we can do is reduce the likelihood and the impact of those disruptions.
"We are acutely aware of the impact the outages had on our customers and we are committed to rebuilding their trust in us by meeting, if not exceeding, those expectations every day."