UKAnon here.

As per a previous notable, the UK and Japan have both been hit by an outage of the O2 / Telefonica mobile network today. Voice has been up / down all day, and mobile data non-existent. This has had a knock-on effect in small shops that use credit card readers tied to the O2 network. In London today, people had to use cash to pay for transactions in some shops. Shock! Horror! Not everyone could cope.

The outage has been traced to an update that was applied to the mobile core by a sub-contractor Ericsson. See here: https://www.ericsson.com/en/press-releases/2018/12/update-on-software-issue-impacting-certain-customers

Following network disturbances in a number of Ericsson’s (NASDAQ:ERIC) customer networks, Ericsson has taken immediate action to minimize impact and support the restoration of services.

During December 6, 2018, Ericsson has 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).

Börje Ekholm, President and CEO, Ericsson, says: “The faulty software that has caused these issues is being decommissioned and we apologize not only to our customers but also to their customers. We work hard to ensure that our customers can limit the impact and restore their services as soon as possible.”

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.

During the course of December 6, most of the affected customers’ network services have been successfully restored. We are working closely with the remaining customers that are still experiencing issues.

One of my phonefag pals who has worked on SGSN says that this kind of upgrade, whilst fairly common generally takes an age to apply - typically 5-7 hours. Ericsson applied an update, rebooted at 5am and everything went splat. With all of the UK mobile operators, a lot of the core functionality is contracted out to third parties. What Ericsson did by accident is what Huawei is suspected of weaponising - hence the move by Five Eyes away from Chinese tech in mobile networks.