An FCC investigation into AT&T’s 911 outage in March concluded the incident could have been prevented if AT&T had implemented network reliability best practices.
According to the report, the outage was sparked when AT&T rolled out a network change that resulted in a mismatch between the trusted set of IP addresses in AT&T’s network and the IP addresses its subcontractor used to send 911 call routing information to the carrier. Though the network attempted to reset itself to remedy the problem, it was unable to restore the connection between AT&T and the subcontractor because the IP issue had not been resolved.
The situation was further exacerbated by the fact that a second subcontractor shared paths to AT&T’s 911 network with the first. As a result, “nearly all 911 calls on AT&T’s VoLTE network” – some 12,539 of them during the five-hour-long March 8 incident – were impacted.
FCC Chairman Ajit Pai on Thursday called the outage “unacceptable” but noted the information gleaned from the investigation could serve as a learning point for other carriers.
“This outage could have been prevented. It was the result of mistakes made by AT&T,” he observed in a statement. “The Bureau’s report shows that there were shortfalls in operational redundancies, risk assessment, and stakeholder and consumer outreach. Had AT&T followed certain best practices as outlined by the FCC’s Communications Security, Reliability and Interoperability Council, this outage would have had much less impact. Indeed, the cause of the outage could and should have been identified and addressed with periodic audits of the network.”
Moving forward, Pai urged other operators to address similar vulnerabilities in their networks, and asked the industry, PSAPs, and consumer groups to collaborate with the Commission to find ways to improve notifications to PSAPs and consumers when 911 outages do occur.