T-Mobile Outage Knocks Out Service for Thousands Across U.S.
A routing failure in the network core disrupted voice and texting Monday evening; executives rule out cyberattack.
T-Mobile customers across the United States lost voice and texting service on Monday, June 15, 2020, in a nationwide outage that left nearly 90,000 users reporting disruptions before repairs were completed around 10:00 p.m. PT.
The carrier confirmed the disruption stemmed from an IP traffic-related routing issue that created significant capacity problems in the network core. Mike Sievert, T-Mobile's CEO, said in a statement: "This is an IP traffic related issue that has created significant capacity issues in the network core throughout the day."
According to Down Detector, approximately 90,000 outage reports were filed during the incident, with nearly 70 percent of users reporting a complete loss of signal. The disruption affected major cities across the country, leaving customers unable to place calls or send text messages for several hours.
T-Mobile executives attributed the root cause to a leased fiber circuit failure from a third-party provider in the Southeast, compounded by a redundancy failure that prevented automatic failover. Neville Ray, T-Mobile's President of Technology, issued an apology once services were restored: "Thank you for your patience as we fixed the issues. We sincerely apologize for any and all inconveniences."
During the outage, social media speculation mounted that a distributed denial of service (DDoS) attack might be responsible. Those rumors were dismissed by Cloudflare CEO Matthew Prince, who stated there were no signs of a coordinated attack or anomalous traffic spikes across major internet services.
The incident underscored the interdependence of major carriers. While Verizon and AT&T networks operated normally throughout the disruption, both companies saw elevated report volumes from users attempting to reach T-Mobile customers.
Service restoration was completed by approximately 10:00 p.m. PT, with Ray confirming via Twitter at 10:03 p.m. PT that calling and texting functionality had returned.
The outage highlights the vulnerability of core network routing infrastructure and the speed at which misinformation can spread during critical service failures. For T-Mobile, which has heavily marketed its network reliability in recent years, the incident serves as a reminder that even well-engineered systems remain susceptible to cascading failures when redundancy mechanisms fail.