SINGAPORE - Singtel has been fined $500,000 - the largest in three years - for an islandwide fibre broadband outage last year that left some 490,000 users cut off from the Web.

The outage on Dec 3 that lasted for nearly 24 hours affected close to 90 per cent of Singtel's fibre broadband user base.

Announcing the fine on Monday (Oct 16), the Info-communications Media Development Authority (IMDA) said its investigations showed that the disruption was triggered by a planned maintenance.

The exercise to install security patches overloaded the servers, which could not process subscribers' request for connection to any website.

IMDA also noted that there were warning signs prior to the incident, but Singtel "had failed to take prompt action".

Specifically, the same servers were almost being fully utilised - at up to 90 per cent.

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In view of the high utilisation rate, Singtel should have exercised "greater due diligence and caution" to prevent overloading the servers when installing the security patches.

When determining the fine, IMDA took into consideration mitigating factors such as the compensation Singtel had offered to affected customers.

For instance, Singtel waived the mobile data charges for those whose fibre broadband access was cut off on Dec 3 as customers were told to surf the Web using their mobile connection. The telco also extended a 10 per cent discount to customers’ fibre broadband bill for the whole of December.

Singtel has also since upgraded its servers to prevent a similar incident from recurring, and is reviewing its broadband network architecture to improve its resilience.

“We deeply regret the fibre broadband service disruption last December. We know how important network reliability is to our customers and we have learnt from this incident.” said Mr Yuen Kuan Moon, Chief Executive Officer of Consumer Singapore at Singtel.

“We have extended $5 million compensation via credits and fee waivers to affected customers, and have taken measures to further strengthen our servers, conducted a review of our broadband network architecture and enhanced the resiliency of the network. Our top priority is to always provide a reliable and secure network and we will continue to channel more resources to ensure our broadband infrastructure meets the growing needs of our customers.”

The largest telco fine of $6 million was meted out in May 2014 to Singtel over a fire at its Bukit Panjang Internet exchange in 2013 that took down phone lines, banking payment and Internet services across Singapore.

In that case, the unprecedented islandwide outage had affected close to 270,000 subscribers including DBS branches and ATMs, SingHealth polyclinics, Singapore Pools branches and AXS payment machines.

Home fibre broadband users of SingTel, StarHub and M1 were also cut off from the Internet, as the fire damaged the cables of national fibre broadband network builder Netlink Trust were housed in the same premises.