KDDI network disruption in early July affected over 30 M. users

Yomiuri Shimbun file photo
KDDI President Makoto Takahashi speaks at a press conference about the company’s service disruption in Chiyoda Ward, Tokyo, on July 3.

TOKYO (Jiji Press) — KDDI Corp. submitted a report on its major network disruption earlier this month to the communications ministry on Thursday, saying that over 30.91 million users in total were affected across Japan.

It was one of the largest network disruptions ever in the country, regarded as a serious incident under the telecommunications business law.

According to the report, the disruption affected voice calls by some 23.16 million users and data communications by over 7.75 million users. The situation continued for 61 hours and 25 minutes from 1:35 a.m. on July 2 to 3 p.m. on July 4.

As the cause of the disruption, the report identifies a setting error during router maintenance work. As many users tried to get reconnected to the network, the major telecom company restricted data flows in order to reduce the load on the network.

KDDI initially said the disruption affected up to 39.15 million subscribers, but has revised the figure based on surveys later.

KDDI plans to compensate millions of subscribers to voice call services only. President Makoto Takahashi is scheduled to hold a press conference on Friday to explain steps to be taken.

Among past mobile network disruptions in Japan, a disruption at SoftBank Corp. in 2018 affected some 30.6 million subscribers for about four hours and a half.

Last year, a glitch occurred at NTT Docomo Inc., affecting over 12.9 million users. The problem took about 29 hours to fully fix.

Over the recent disruption, KDDI took about 86 hours to declare the full restoration of its network, causing widespread confusion in society.