April 28, 2023 Receipt of Serious Accident Reports submitted by Nippon Telegraph and Telephone East Corporation and Nippon Telegraph and Telephone West Corporation

The Ministry of Internal Affairs and Communications (MIC) received today (April 28, 2023) separate serious accident reports from both Nippon Telegraph and Telephone East Corporation (NTT East), led by President SHIBUTANI Naoki, and Nippon Telegraph and Telephone West Corporation (NTT West), led by President MORIBAYASHI Masaaki. These reports address a communications failure that occurred on Monday, April 3, 2023, and were submitted in accordance with Article 28 of the Telecommunications Business Act (Act No. 86 of 1984).

1. Background

On Monday, April 3, 2023, the communications failure occurred with respect to the communications services (Optical Access Service and Hikari Denwa Service, including the Hikari Collaboration Model) provided by NTT East and NTT West. Today, MIC received separate serious accident reports from both companies, in accordance with Article 28 of the Telecommunications Business Act, detailing the occurrence, causes, and measures to prevent a recurrence, etc., of the said failure.

2. Future plans

MIC will examine the contents of the said reports closely and consider any necessary action.
*The reference material is in Japanese only.