On Monday, Nippon Telegraph and Telephone East Corp. (NTT East) and Nippon Telegraph and Telephone West Corp. (NTT West) experienced major network disruptions affecting users of their Flet’s Hikari fiber optic Internet connection service and Hikari Denwa telephone service.
The equipment failure, which began at approximately 7:10 a.m., affected parts of Tokyo, Osaka, and other prefectures nationwide.
In addition, Hikari Denwa users could not make calls, including emergencies.
NTT East and NTT West are currently working to restore services and have apologized for the disruption, urging affected customers to use mobile phones or public telephones for emergency calls.
More than 260,000 FLET’S Hikari and 140,000 Hikari Denwa calls were involved, and emergency services such as 110 and 119 were also out of service.
NTT East has since announced that the situation has been resolved.
NTT West also experienced a similar outage due to a malfunction in equipment used for optical services, but this has now been restored.
Softbank, another major telecommunications company, reported difficulties using its fiber optic service, Softbank Hikari, and other services due to the incident.
The outage affected areas in 13 prefectures, including Hokkaido, Tokyo, and Osaka.