Telstra must spend more money on its network or risk losing customers, analysts say, after a fifth outage hit the telco giant's network on Sunday.
Telstra's network is back up and running on Monday following the latest problem, which the company blamed on a piece of faulty hardware.
Some Telstra mobile customers experienced "a brief interruption" to data services, a company spokesperson said.
The problem affected customers in NSW mainly, although some other states were also affected.
The incident came just two days after another network issue prevented some NBN and ADSL users connecting to the internet on Friday and in the wake of three more outages of varying degrees of seriousness since February.
For Friday's outage, Telstra pledged to give affected customers with "some additional data" but so far has not provided any details of the compensation offer.
But Foad Fadaghi, principal analyst at research firm Telsyte, said free data is a limited strategy.
Mr Fadaghi said Telstra's decision to give mobile customers free data on two separate days following its last two major network outages are merely "short term fixes".
Instead, the company needs to fork out more than the additional $50 million it recently committed to spend on improving its network, he said.
"The amount of money that has been set aside is nowhere near enough in terms of what needs to happen to fix the situation," Mr Fadaghi said.
Telstra must provide a reliable, fast service to customers, who have become increasingly reliant on the internet for work, social services and shopping, especially as they charge a premium for their network, Mr Fadaghi told AAP.
Telstra claims to have the best network in the country with around 16.9 million mobile subscribers.
The company has blamed the spate of problems on human error, an overseas connection problem, a technical failure, a device fault and a piece of faulty hardware.
On May 2, Telstra announced it would invest a further $50 million in its network following a resilience review, which looked at the group's first three network problems in February and March.
On the same day, Telstra committed to returning at least $1.5 billion to shareholders following the selldown of its stake in Chinese online carsales business Autohome.
Paul Budde, managing director of telecommunications research and consultancy group Paul Budde Communication, said the network outages indicate "some very serious problems" deep in the network.
"There is clearly something far more fundamentally wrong within their system. Something apparently that is very hard to fix," Mr Budde told AAP.
Rivals, including Vodafone Hutchison Australia and Optus are potential beneficiaries as Telstra comes under a barrage of criticism from customers on social media.
VHA - a 50/50 joint venture between Vodafone Group and Hutchison Telecommunications in Australia - recently started to win back customers following its extensive "Vodafail" network problems at the end of 2010.
Optus, which is owned by Singapore Telecommunications, is pursuing a content strategy in a bid to attract more mobile and internet customers.
