Businesses and consumers have asked why no backup plans were in place after a fire at one of nine major SingTel Internet exchanges crippled essential services across the island for more than 24 hours.
Mr Benjamin Tan, managing director of Internet service provider SuperInternet, said that it is common for providers of critical services like banks and hospitals to buy backup services from Internet service providers (ISPs).
Such backup services divert Internet traffic to an alternative route should the main cables be cut off - as in the case of SingTel.
"When there is a prolonged disruption like this, you can safely say that either the banks and hospitals did not buy the backup service, or the ISP's contingency plans did not kick in," said Mr Tan.
DBS Bank said yesterday that it was working with SingTel to work out why the network contingency plan that it had signed up for did not function as expected for the 18 branches affected by the blaze.
The bank said it has duplicated several layers of critical systems to improve the network's reliability. This enabled the vast majority of its banking services to avoid any impact from the disruption.
A spokesman for M1 said that it will pursue OpenNet's lack of backup plans with the Infocomm Development Authority of Singapore.
M1 had about 1,000 fibre broadband customers affected as two-thirds of the damaged cables belong to OpenNet, the builder of Singapore's ultra-fast fibre broadband network.
Asked about backup plans, SingTel said it had a "robust system in place to minimise outage in adverse situations".
Unfortunately, in this case, it added, though it was able to divert some of the affected services to alternative cables, the damaged lines had to be repaired by hand.
Several consumers The Straits Times spoke to yesterday evening said services to their homes were still down.
Financial adviser Tan Chen Hong, 29, said he was still not able to surf the Web on his broadband connection or make phone calls from his home in Woodlands as of 9pm yesterday.
"I was so frustrated. I was working from home but couldn't be connected to the real world," said the SingTel subscriber.
Mr Sallihin Othman, 28, a civil servant, had his SingTel mobile phone, broadband and mioTV service disrupted. "I wish I had subscribed to other telcos," he said. "The restoration is not happening fast enough."
Additional reporting by Yeo Sam Jo and Nur Asyiqin Mohamad Salleh