O2 is reportedly seeking tens of millions of pounds in compensation from Swedish networking giant Ericsson following the nationwide mobile data outage last week, which was caused by an expired software certificate.
According to a report by The Telegraph, O2 and parent company Telefonica will negotiate with Ericsson over the bill, which the publication understands to be around the £100 million mark.
The Guardian reported that Telefonica O2 UK CEO Mark Evans will meet with Ericsson executives this week to discuss the latter's software, as well as how it was managed.
An expired certificate was the cause of the data outage that not only affected O2 in the UK, but also SoftBank mobile services in Japan, Ericsson had revealed on Thursday.
"An initial root cause analysis indicates that the main issue was an expired certificate in the software versions installed with these customers," Ericsson said last week.
"A complete and comprehensive root cause analysis is still in progress. Our focus is now on solving the immediate issues."
The issue affected nodes in the core networks of customers using two software versions of the Serving GPRS Support Node - Mobility Management Entity (SGSN-MME), Ericsson said, adding that it had taken immediate action to enable service restoration.
"The faulty software that has caused these issues is being decommissioned, and we apologise not only to our customers but also to their customers," Ericsson CEO Börje Ekholm said at the time.
Earlier on Thursday, O2 had said the data network outage was the result of a "global software issue".
On Friday, O2 then confirmed that the outage had ended, with 3G data restored at around 9.30pm local time on Thursday.
"Our technical teams will continue to monitor service performance closely and we're starting the full review to understand what happened. We are really sorry for the issues yesterday," the company said.
Over in Japan, SoftBank said its outage extended from 1.39pm until 6.04pm JST on Thursday, with SoftBank and Y!mobile 4G LTE mobile phone services, Ouchi-No-Denwa fixed-line services, and SoftBank Air services affected.
The outage was "caused by Ericsson-made software errors related to its packet switches, covering our customers nationwide", SoftBank explained. It is still investigating how many customers were impacted.
"At 1.39pm on Thursday, December 6, 2018, the SoftBank Network Center detected software's malfunction in all of the packet switching machines manufactured by Ericsson, which are installed at the Tokyo Center and the Osaka Center, covering our mobile customers nationwide," SoftBank said.
"After the incident, SoftBank received a report from Ericsson that the software has been in operation since nine months ago and the failure caused by the same software also occurred simultaneously in other telecom carriers across 11 countries, which installed the same Ericsson-made devices.
"The network was recovered to the normal operation by adapting the older version of the software to all packet switching machines."
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