Telstra has said its network is back up and running after the telecommunications provider resolved a four-hour outage that prevented around 75,000 customers from accessing broadband services on Saturday.
"From around midday AEST to 4pm on Saturday, some of our broadband customers were unable to establish an internet connection," a Telstra spokersperson said.
"Approximately 75,000 customers were directly affected. The issue has now been resolved and we apologise for any inconvenience."
The outage affected customers across the country, with technology rather than geographic location being the cause for those who faced the outage.
Telstra last month similarly experienced a National Broadband Network (NBN) and ADSL outage affecting around 370,000 customers, caused by modems misbehaving after a domain name server (DNS) software failure.
"A software update to one of our domain name servers caused that server to go down. It had a flow-on effect to our customers' modems, and they couldn't undertake the regular check they normally do in that environment," Telstra COO Kate McKenzie said in May.
"We actually fixed the software bug overnight on Thursday night, and on Friday morning, we had thought that the problem was resolved ... we didn't anticipate the flow-on effect; a number of the modems sitting on the end of the network didn't behave in the way that they were supposed to."
While 370,000 customers were affected initially, by the following morning only 1 percent of customers, or 33,000, were impacted. Still affected a week later were around 0.5 percent of Telstra's customer base, or 15,000 people.
As a result, Telstra resorted to sending out new modems to the thousands of customers in an effort to bring them back online, as well as taking money off their monthly bill.
Telstra had a rough start to 2016, with customers subjected to three major 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.
The first three outages led Telstra to commit to spending an additional AU$50 million on improving the monitoring and recovery times of its network.
Telstra also experienced a mobile data services outage last month. Mike Wright, group managing director of Networks, attributed it to a hardware failure in one of the telco's gateways in New South Wales.
"Every state has two gateways that lets our customers contact the internet," Wright explained.
"It was a hardware failure in a card, and while it switched over, what the devices often have to do is be put back into either flight mode or turned off and on so they reconnect to the other gateways, so Sunday morning that was basically a fail over a bit of hardware."