The FCC said it would investigate what caused T-Mobile’s recent nationwide outage and that process began yesterday. On June 15, the carrier had what the agency calls “a substantial outage” preventing customers from making and receiving calls, and, in some cases, sending texts to T-Mobile’s Voice-over LTE (VoLTE) network.
T-Mobile said the outage was caused by “a leased fiber circuit failure from a third-party provider in the Southeast.” The circuit overloaded and caused “an IP traffic storm that spread from the Southeast to create significant capacity issues across the IP Multimedia Subsystem core network that supports [its] VoLTE calls,” the carrier said.
The Public Safety and Homeland Security Bureau is conducting an investigation into this outage, given its size and scope; the FCC’s also trying to determine the veracity of social media posts that said 911 calls were impacted as well.
The bureau seeks public comment on relevant information concerning the causes, effects, and implications of the outage. It wants to know how public safety entities, as well as state and local governments, were impacted.
The Commission asks questions such as: Are there estimates of how many calls, including 911 calls, failed or otherwise affected by the outage? What was the effect of the outage on public safety activities and government services across the country? The agency also seeks input about the impact on Public Safety Answering Points.
Were customers of T-Mobile’s network able to successfully make or receive all calls, some calls, or no calls at all, the Commission wants to know. Public comments are due [to PS Docket 20-183] on or before July 8.