SOFTBANK MOBILE announces the cause of large-scale network failure affecting about 80% of users

SOFTBANK MOBILE officially announced the cause of large-scale network failure that occurred over 6 hours from 9:09 to 15:58 on Sunday, April 19, 2009.

The maximum number of cases affected was about 15.76 million contracts, which is a network problem affecting about 80% of SOFTBANK MOBILE users, but what was the cause? In addition, SOFTBANK MOBILE receives guidance from the Ministry of Internal Affairs and Communications on the assumption that a serious communication failure accident has been repeated in the past.

Details are as follows.
About Packet Communication Service Failure Occurring on April 19th | SOFTBANK MOBILE Corp.

According to this release, it seems that a large-scale network failure occurred at SOFTBANK MOBILE from 9:09 to 15:58 on Sunday, April 19, 2009. The cause is "network equipment malfunction", we will continue to pursue the cause and continue to tackle the reoccurrence with the whole company.

Due to this network failure, users using third generation mobile phone services in Hokkaido, Tohoku, Tohoku, Kanto, Koushin'etsu, and Tokai regions will receive "Yahoo! Keitai" "S! Mail" from 9:09 to 12:59 In addition to becoming unusable, it seems that there was a situation where the reception of "S! Mail" was delayed from 9:09 to 15:58.

The number of affected cases was a maximum of 15.76 million contracts, accounting for approximately 76.4% of SOFTBANK MOBILE 's subscribers as of the end of March of approximately 206.3 million.

By the way, SOFTBANK MOBILE, in May last yearWe received guidance from the Ministry of Internal Affairs and Communications on the assumption that serious communication failure accidents have occurred repeatedlyHowever, the relevant requirements of "serious accident" are as follows, so this communication failure seems to apply.

1. The number of users affected by suspension of service provision or deterioration in quality is more than 30,000
2. Suspension of service or degradation of quality over 2 hours