IMDA fines Singtel S$1 million for Oct. 2024 outage that affected emergency services

Singtel has been fined S$1 million by the Infocomm Media Development Authority (IMDA) for a widespread service outrage that occurred on Oct. 8, 2024.

The outage, which lasted more than four hours and affected about 500,000 residential and corporate users, also disrupted the public's access to a number of customer service lines, including healthcare organisations and emergency call services.

In a statement on Dec. 11, 2025, IMDA said it takes "a serious view of the incident" and conducted a thorough investigation following the incident.

Fixed voice disruption

Investigations found that the outage was caused by a disruption in Singtel's fixed voice system.

The service provider hosted two separate virtualised firewalls on the same hardware, one for its fixed-line voice system (“voice system”) and another for the monitoring system for home broadband routers and Pay TV set-top boxes (“monitoring system”).

This meant that both virtualised firewalls shared the same hardware memory resources.

However, as the monitoring system's virtualised firewall did not have adequate filters installed to protect the hardware against high intensity traffic, the shared memory resources of the hardware were overwhelmed by high traffic intensity on Oct. 8, 2024.

This caused the virtualised firewall of the voice system to also malfunction, which in turn led to voice traffic being unable to be redirected seamlessly to a separate unaffected voice system via a failover mechanism.

From the user's point of view, this meant calls were dropped intermittently as voice traffic alternated between the affected and unaffected voice systems.

The issue was solved after Singtel redirected all voice traffic to the unaffected voice system.

Penalty

IMDA said the S$1 million penalty imposed took into account the scale and impact of the disruption, as well as the time taken to restore the network.

"The potential impact on the safety and security of the public could have been very serious," they said, addressing the fact that public access to key hotlines were affected.

They also found that the incident was not due to a cyber-attack, and concluded that it was preventable within Singtel's control.

Singtel said it has since taken necessary measure to prevent potential re-occurrences, including installing separate hardwares for its voice system and monitoring system.

An intervention mechanism was also implemented to stop network traffic from alternating between systems during failovers.

Oct. 8, 2024 incident

The outage occured between 2pm to 4pm on Oct. 8, 2024, during which customers experiences difficulties reaching hospitals, banks and emergency lines like Singapore Civil Defence Force (SCDF), Singapore Police Force (SPF), and KK Women's and Children's Hospital.

In that time, a number of these services requested members of the public sent them messages and emails instead.

Singtel subsequently announced that the its fixed voice services had been fully restored by about 8:25pm the same night, while IMDA announced that it would be launching an investigation to determine the cause of the problem.

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