The Federal Communications Commission (FCC) issued a report today detailing the cause and impact of a major nationwide AT&T wireless service outage on February 22, 2024.
The outage, which lasted at least 12 hours, prevented customers from using voice and data services and blocked more than 92 million phone calls, including over 25,000 attempts to reach 911. The report also includes recommendations to help prevent similar outages in the future.
“When you sign up for wireless service, you expect it will be available when you need it – especially for emergencies,” said FCC Chairwoman Jessica Rosenworcel. “This ‘sunny day’ outage prevented consumers across the country from communicating, including by blocking 911 calls, and stopped public safety personnel from using FirstNet. We take this incident seriously and are working to provide accountability for this lapse in service and prevent similar outages in the future.”
The FCC’s Public Safety and Homeland Security Bureau launched an investigation immediately after the outage occurred. Key findings from the report include:
The outage affected users in all 50 states, Washington, D.C., Puerto Rico, and the U.S. Virgin Islands. All voice and 5G data services for AT&T wireless customers were unavailable, affecting more than 125 million devices, blocking over 92 million voice calls, and preventing more than 25,000 calls to 911 call centers.
Customers of other wireless providers that use or roam on AT&T’s network also experienced service disruptions.
It took AT&T at least 12 hours to fully restore service.
The outage cut off service to devices operated by public safety users of the First Responder Network Authority (FirstNet). AT&T prioritized restoring FirstNet before other services but did not notify FirstNet customers of the outage until three hours after it began, and nearly one hour after service was restored.
The incident was triggered by a network change with an equipment configuration error. The report details multiple factors that contributed to the extensive scope and duration of the outage and outlines the corrective actions AT&T has taken to prevent a recurrence.
The report emphasizes the need for network operators to follow internal procedures and industry best practices when implementing network changes. It also highlights the importance of having sufficient network controls to prevent configuration errors from escalating and disrupting network operations. Furthermore, the report calls for appropriate systems and procedures with adequate capacity to facilitate prompt recovery from large-scale outages.
Based on its investigation, the Public Safety and Homeland Security Bureau has referred this matter to the Enforcement Bureau for potential violations of FCC rules. Additionally, the FCC is investigating a recently disclosed AT&T breach of consumer data and is working closely with law enforcement agencies.