Singtel landline outage: Backup system did not work as intended after 'technical issue'

SINGAPORE: The hours-long Singtel landline outage last month was caused by a "technical issue" of a network component, Senior Minister of State for the Ministry of Digital Development and Information Janil Puthucheary said on Monday (Nov 11), citing preliminary findings.

A backup system also did not kick in as intended.

Speaking in parliament, Dr Janil said preliminary findings suggest that the technical issue affected the proper functioning of a network component in one of the two systems supporting Singtel’s fixed-line voice service.

The two systems, located in separate telephone exchanges, are designed to immediately take over the full load of the other when one system malfunctions, he said.

"However, in this instance, the failover did not happen seamlessly, which caused the intermittent service disruption," he explained.

The Singtel landline outage on Oct 8 disrupted calls to emergency services, healthcare institutions, as well as customer service lines for some government agencies, banks and businesses.

Members of Parliament had filed several questions on the matter, including what could have caused the disruption, how such an incident could be prevented in future and whether any action would be taken against Singtel.

Dr Janil said there is no evidence to suggest that the incident was related to a sabotage or cyberattack, adding that the Infocomm Media Development Authority (IMDA) is continuing its investigations.

"The telecommunication network in Singapore is a key infrastructure that supports our nation’s connectivity needs and requirements. IMDA holds key service providers, like Singtel, to high service standards and requires them to conduct regular audits on their network and infrastructure," he said.

"This includes ensuring the security of network design, redundancy measures, and business continuity plans. Service providers must also ensure that their networks are resilient against disruptions. IMDA will not hesitate to take strong action under the Telecommunication Act, including imposing financial penalties, should any lapses be identified."

Responding to a supplementary question from Dr Tan Wu Meng (PAP-Jurong), Dr Janil said that Singtel is held to a "very high level" of reliability through the current regulatory framework.

AFTER-ACTION REVIEW TO BE CONDUCTED

During the disruption, it is estimated that half of the calls could still be connected, Dr Janil said, noting that all services were progressively restored over four hours after the start of the incident.

Singtel previously said the disruption was an "isolated incident".

Calls to 995 and 999 were among those affected. IMDA said on Oct 8 that Singtel was required to restore services urgently, with emphasis on key government services. 

Minister of State for Home Affairs Sun Xueling said that when the Singapore Civil Defence Force (SCDF) and Singapore Police Force (SPF) learnt of the "technical difficulties" faced by some callers, the public was informed to contact them via SMS. They could also report incidents through the SGSecure app.

"Arising from that incident, there was no feedback from the public on SCDF and SPF failure to respond to any urgent or life-threatening incident," she added.

IMDA is working with the Ministry of Home Affairs, SCDF and the SPF to conduct a comprehensive after-action review on the availability of Singapore's emergency hotlines when disruptions occur, said Dr Janil.