FCC Says T-Moblie’s Failure to Use Industry Best Practices Caused June Outage

According to a press release issued Thursday, the Federal Communications Commission (FCC) determined the causes and impact of a nationwide T-Mobile network outage that occurred over the summer. The report cited equipment failure, moving to a new router, and a software flaw. 

FCC Chairman Ajit Pai said “T-Mobile’s outage was a failure.” He explained that the investigation revealed the company’s failure to follow established reliability best practices. “All telecommunications providers must ensure they are adhering to relevant industry best practices, and I encourage network reliability standards bodies to apply their expertise to the issues identified in this report for further study,” Pai counseled.

The Public Safety and Homeland Security Bureau’s (PSHSB) report marks the culmination of an investigation the FCC began in June. Additionally, it made findings regarding network reliability measures that can be taken to safeguard against similar outages in the future.

The report explained that the outage began midday on Jun. 15, and lasted more than 12 hours. It disrupted calling and texting services nationwide, emergency services connectivity, and data access in some areas. The FCC’s PSHSB estimates that “at least 41% of all calls that attempted to use T-Mobile’s network during the outage failed, including at least 23,621 failed calls to 911.”

The initial outage was attributed to an equipment failure, but that outage was aggravated by a “network routing misconfiguration that occurred when T-Mobile introduced a new router into its network.” Another exacerbating factor was a software flaw in the network that had been hidden for months and interfered with users’ ability to initiate and accept voice calls during the outage.

The report found that using network reliability best practices could have prevented or lessened the effects of the outage. It also recommended further network reliability study by standard bodies. In terms of action, the FCC said it will release a public notice advising telecommunications providers of industry-accepted best practices, will discuss network practices with major transport providers, and will strive to aid smaller providers to ensure national network vitality.