Vodafone Australia has confirmed that its four-hour outage across voice services has been resolved, attributing the issue to a fault during scheduled work.
"An earlier issue which caused intermittent disruption to voice services for some customers has now been resolved," a Vodafone spokesperson said.
"The issue, which was caused by a fault during scheduled work on the network, resulted in voice traffic congestion from 10.30am AEDT. The issue was fully resolved by 2.30pm AEDT."
Vodafone had confirmed the outage earlier on Wednesday via a tweet following customer complaints, saying the issue was affecting some customers' ability to make and receive calls on the mobile network -- though one customer claiming that their data services have been impacted.
"We are working to resolve ASAP an issue causing intermittent disruption to voice services for some customers. We expect this to be resolved shortly," a Vodafone spokesperson said.
"Data and text services are not affected. We apologise to customers for any inconvenience and thank them for their patience."
Vodafone suffered another voice outage lasting around three hours back in January, which was caused by an error during planned work on the network.
The telecommunications carrier also suffered a seven-hour 4G mobile outage affecting data, voice, and text messages back in September last year, which was caused by a router issue.
The router issue subsequently led to a high number of customers attempting to use the 2G and 3G networks, with a high level of congestion following.
Vodafone backs up the reliability of its mobile network with a 30-day money-back network satisfaction guarantee.
As of December 31, Vodafone's post-paid customers totalled 3.35 million, while prepaid customers numbered 1.65 million and MVNO customers reached 556,000, for a total network customer base of 5.56 million.
Despite gaining 125,000 customers over calendar 2016, market research company Kantar reported that Vodafone again experienced losses in total mobile market share -- it now holds 14 percent of the total mobile market, made up of 13.2 percent of the prepaid market, 15.5 percent of the post-paid market, and 9.3 percent of the no-contract segment.
The Productivity Commission's draft report into the telecommunications universal service obligation (USO), released in December, revealed that although Vodafone claims to have 96 percent of the Australian population covered by its network, or 23 million people, only 7.5 percent of the continent's landmass is covered.
By contrast, Optus claims 98.5 percent population coverage and covers 15.6 percent of the nation, while Telstra's 99.3 percent of the population amounts to covering more than 31 percent of the landmass with its mobile network.
Vodafone reported a net loss of AU$241.8 million for the year on total revenue of AU$3.35 billion, an 8.4 percent year-on-year decrease, with earnings before interest, tax, depreciation, and amortisation (EBITDA) of AU$912.2 million, a 12.2 percent increase.
Updated at 3.20pm AEDT, March 15, 2017: The issue has now been resolved.