Japan’s second biggest telco finally fixes network after three-day outage

The Japanese telco KDDI has said that it has fixed a problem with its network which affected over 39 million users for over three days.

KDDI users were unable to access the internet or make voice calls in what is one of the country’s worst-ever network outages, as reported by the Japan Times. It also impacted service providers in sectors like banking, weather, logistics, and health care.

The operator experienced network failure on Saturday 2 July at around 1:35 am when it replaced a router for its core network as part of regular maintenance, which ended up preventing the connection of voice calls. The carrier attempted to fix the problem but experienced a heavy amount of traffic which exacerbated connection difficulties.

The company said on Monday that the network was almost restored and more or less stable, but it needed to keep monitoring it to ensure it had fully recovered. KDDI also said it would consider offering compensation to users.

"We deeply regret this as a telecommunications carrier in a position to support critical infrastructure and provide stable services," said Makoto Takahashi, KDDI president, according to Reuters. He said it was the biggest system failure in the carrier's history.

Around 70% of the network’s services had recovered by mid-morning on Sunday and KDDI planned to recover the rest by around 5:30 pm, said Takahashi. However, problems persisted until after this deadline, with the company only confirming that it had fixed the network today.

Earlier today, Japan’s communications minister, Yasushi Kaneko, criticised the company and said it had not fulfilled its responsibility as a telecommunications operator. Kaneko added that due to the unprecedented impact of the outage, the government will set up an expert panel to compile measures to prevent a recurrence.

"It is extremely regrettable that it has got to the point of potentially threatening people's lives and we are taking the situation seriously,” said Kaneko, referring to the disruption of emergency calls during the outage.

The Meteorological Agency has also demanded that the organisation come up with measures to prevent the incident from occurring again after some data distributions from its regional weather observation system were suspended. It has around 1,300 observation stations across the country, of which 550 had stopped transmitting data because of the network disruption.

In the health sector, some medical facilities had difficulty in communication with doctors and drivers who were delivering pulse oximeters to coronavirus patients due to the disruption, revealed health minister Shigeyuki Goto.

"To ensure there is no serious interference to medical and nursing-care services, we will work with prefectural governments to secure a stable system from normal times," said Goto.

Japan’s largest mobile telco, NTT, experienced a similar outage in October last year which lasted for around 29 hours and impacted 12.9 million users.