Another Telstra network outage this week has drawn a line in the sand. This issue has now moved from being just a problem for customers, to being a real problem for the company.

No longer can Telstra explain away this series of network mishaps as just bad luck - the operation of chance when dealing with large, complex communications networks. The frequency has now become the big issue.

This week's outage, although not as widespread as some of the previous ones, has had more onerous consequences.

It hit the operations of an airline, a bank, a large department store chain, Medibank, the Department of Finance, and even political parties on the eve of an election, plus myriad businesses on the all-important final day of the financial year.

The ripple effect was significant.

Customers pay a hefty premium when they sign up for Telstra's network products, be they fixed or mobile, on the basis of a superior network. And while the company maintains it delivers a better and more reliable service than competitors, this week's outage will bring those claims into question.

The timing of this latest outage was all the more embarrassing for Telstra given it hit the day after the company's chief executive, Andy Penn, announced it would be redirecting $250 million in capital expenditure to improve the network infrastructure.

The decision suggests the company sees the problems with the networks as being more systemic than one-off.

At a journalist briefing earlier this week, Telstra refused to provide any update on whether it had lost customers due to the network's problems. This won't be known until the June 30 financial report is delivered in August.

But it is clear the issues with the performance of the Telstra network have had a negative effect on customer service scores (net promoter scores ), which in turn are linked to staff and management bonuses.

Penn said this week he would be losing a portion of his bonus. In a letter to staff a few weeks ago, Penn said the company was unlikely to meet its full-year net promoter score target and staff bonus incentives would suffer.

"While there is no doubt our advocacy efforts have been challenged in recent months by network interruptions, it is also clear we continue to be held back by some ongoing systemic customer service issues.

The trouble for Telstra is that it may struggle to retain its premium price if the network is perceived to be unreliable, which in turn could force it to cut its prices to salvage its customer base.

Even if it doesn't lose too many customers, it will find it more difficult to add new subscribers.

Penn's mea culpa the day before the latest outage may not be enough to convince current and would-be customers that a $250 million rectification isn't too little, too late.

"Over the past few months, we have experienced some network interruptions that have impacted you, our customers. All of us at Telstra are deeply sorry for the inconvenience this has caused," he said.

The networks business sits at the heart of almost everything Telstra does. Competition in fixed-line services is already under pressure thanks to the migration to the national broadband network (NBN), and in mobiles the other major players, Optus and Vodafone, have been biting at Telstra's heels with cheap data plans. They have also been spending big on improving their networks.

In an attempt to assess the potential damage to Telstra's business (before the latest outage), analysts from Deutshe Bank conducted a survey of customers that suggested mobile churn could increase from 11 per cent to 19 per cent and fixed data churn was also likely to increase.

According to the Deutsche report, this is despite the fact that there was no significant change in the perception of Telstra's network quality following earlier outages.

Had the survey been conducted this week, the findings may have changed. On the back of these findings, the Deutsche analysts downgraded their expectations for Telstra's earnings per share by 5 per cent in 2017.

"Following our earnings changes, we are now forecasting Telstra delivering -6% income growth and -1% EBITDA [earnings before interest, tax, depreciation and amortisation] growth in FY17. Our forecasts are 6-8% below FY17 and 10% below FY18 consensus income and EBITDA," they said.