Singtel is still investigating the root cause of a fibre broadband outage that saw its users cut off from Web surfing for 3½ hours yesterday morning, but it has ruled out a cyber attack.
“We do not believe it was a cyber security-related incident,” a spokesman said.
The telco notified customers of the disruption via a Facebook post around 9am, saying its engineers were investigating the problem. At 11am, the telco said Internet access had been restored.
During the outage, even online payments provider AXS' website and app, which run on Singtel's fibre broadband network, could not be accessed.
The Infocomm Media Development Authority (IMDA) said on its Facebook page that it has started its own investigations into the outage.
Users started complaining online from 7.30am, reporting outage in areas as far apart as Choa Chu Kang, Woodlands, Punggol, Toa Payoh, Bukit Panjang, Tampines and Jurong. An error message appeared, pointing to problems with Singtel's domain name system (DNS), which maps Web addresses to a machine-readable string of numbers to connect Internet users to websites.
Mr Aloysius Cheang, Asia-Pacific executive vice-president of the Centre for Strategic Cyberspace + Security Science, a London-based think-tank, said: "Singtel's network could have been overwhelmed by heightened use of certain applications such as virtual private networks (VPNs) and online gaming access as a result of the World Cup."
Besides being used to secure corporate networks, VPN technologies are also used by some people to access blocked or illegal content.
AXS assistant chief executive Chin Mun Chung said the outage affected only its website and the AXS bill payment app. The physical AXS stations were not affected.
Software engineer Zhang Xuanrong, 27, said when he realised that Singtel's DNS was down, he switched to Google's DNS. "It worked for me after that," he said.
University student Howard Wong, 23, was trying to register for a course when his Internet access was disrupted. "In the end, I was not able to secure an important module, which is on first come, first served basis, and I might have to take it next semester," he said.
A senior marketing specialist who wanted to be known only as Ms Di, 40, had taken leave to help her son with his home-based learning assignments. "I restarted the router at least five times, but each time, it worked for less than five minutes before going down again," she said.
Last October, Singtel was fined $500,000 for a 24-hour islandwide fibre broadband outage in 2016 that left about 490,000 users cut off from the Web.
- Additional reporting by Jasia Shamdasani