Singtel's fixed-voice outage cut emergency calls for 500,000 users and drew a S$1M fine

On 8 October 2024, a fault in Singtel's fixed network knocked out the fixed-voice service for about 500,000 users across Singapore, including access to emergency-call services. The outage began in the afternoon and the network was restored that evening, but it left a large slice of the country unable to reach emergency numbers in the meantime.

Singapore's telecom regulator IMDA investigated and, in December 2025, fined Singtel S$1 million. IMDA found the root cause was a design lapse: two virtualised firewalls on the network were sharing one physical hardware platform — a single point of failure — and a traffic spike overloaded the memory, causing the systems to fail.

IMDA's investigation also found operational shortcomings in how Singtel managed network changes and responded to the incident. The regulator said the penalty reflected the seriousness of a failure that touched emergency-call services, and it required Singtel to fix the network design and improve its incident management.

Two virtualised firewalls shared one physical platform, a single point of failure; the spike crashed them, costing a S$1M fine and a mandated redesign.

Singtel ran two virtualised firewalls on one physical hardware platform, making the network design a single point of failure.

A traffic spike overloaded the shared memory, so a demand surge — not a weather event or a physical fault — brought the service down.

Because it touched emergency-call access, the outage drew a regulator fine and a directed overhaul of Singtel's network configuration and incident handling.

A network's virtualised firewalls must run on separate physical hardware — sharing one box makes a single point of failure out of the very firewall that is meant to protect the service.

IMDA fined Singtel S$1 million and required it to eliminate the single point of failure and improve how it manages network changes and incidents.