Ericsson apologises for O2 network outage

The data network crash, which affected millions of people worldwide, was caused by an expired software certificate

O2 has said that the software issue that left millions of customers unable to use any data services worldwide yesterday was down to a flaw in Ericsson certificates.

The fault also affected Japanese users of the SoftBank network, as well as carriers who use O2's network like Sky Mobile, GiffGaff and Tesco Mobile. TfL's timetable service and some NHS trusts were also affected.

Ericsson, which manufactures much of the equipment used in modern cellular networks, says that the fault was due to an expired software certificate in a version of its management software.

The company said, ‘During December 6, 2018, Ericsson...identified an issue in certain nodes in the core network resulting in network disturbances for a limited number of customers in multiple countries using two specific software versions of the SGSN-MME (Serving GPRS Support Node - Mobility Management Entity).'

It added, ‘An initial root cause analysis indicates that the main issue was an expired certificate in the software versions installed with these customers. A complete and comprehensive root cause analysis is still in progress. Our focus is now on solving the immediate issues.'

Ericsson has now restored service to most customers, with CEO Börje Ekholm hurrying to put out fires (although not literally):

"The faulty software that has caused these issues is being decommissioned and we apologise not only to our customers but also to their customers," he said. "We work hard to ensure that our customers can limit the impact and restore their services as soon as possible."

O2's data network went down at around 4:45am yesterday morning, with the immediate and downstream outage affecting around 32 million people (so describing them as ‘a limited number of customers' seems a little off, Ericsson). The company has now restored most connections.

SoftBank's network was not affected for as long, from about 13:39 (4:39 GMT) until just after 18:00 (9:00 GMT), local time. The company has about 40 million mobile customers, although the outage was mostly limited to those in Tokyo and Osaka.