UPDATE: Ray around 1 a.m.
ET that service had been restored.
In a statement, CEO Mike Sievert said the disruption was "an IP traffic-related issue that has created significant capacity issues in the network core throughout the day."
As the outage hit, there was a lot of chatter online about it being the result of a distributed denial of service (DDoS) attack.
But Matthew Prince, CEO of internet security firm Cloudflare, threw cold water on that, arguing on Twitter that "the reality is far more boring."
T-Mobile was "making some changes to their network configurations today.
Unfortunately, it went badly," Prince wrote last night.
"The result has been for around the last 6 hours a series of cascading failures for their users, impacting both their voice and data networks."
But while Prince says the outage was just T-Mobile having a "bad day," FCC Chairman Ajit Pai that it was "unacceptable" and revealed that the FCC "is launching an investigation [and] demanding answers—and so are American consumers."
Original Story:
T-Mobile is currently experiencing an outage affecting voice and data service on its network.
Neville Ray, President of Technology at T-Mobile, around 4:15 p.m.
ET that "Our engineers are working to resolve a voice and data issue that has been affecting customers around the country.
We’re sorry for the inconvenience and hope to have this fixed shortly."
Just after 6 p.m.
ET, Ray followed up to say that work continues but "data services are now available & some calls are completing."
Customers on other carriers are also reporting issues this afternoon, but those carriers appear to be placing the blame on T-Mobile.
"We can confirm our network is operating normally," AT&T tweeted.
"There is an issue with another provider." Verizon its network is "performing well," though customers might have difficulty calling T-Mobile customers.
T-Mobile
Below are the latest status updates from Downdetector.com, which offers real-time internet outage monitoring.
T-Mobile had just over 43,000 reports of trouble on its network at 4:39 p.m.
ET.
At this point, approximately 43 percent of those reports are for no signal; 22 percent are for trouble with mobile internet.
T-Mobile is recommended that people try third-party calling apps (FaceTime, WhatsApp, and Signal) for now.
Among Daxdi staffers, one T-Mobile user said calls had dropped to 3G but were going through; another on Mint Mobile, which uses T-Mobile's network, had trouble placing calls.
AT&T
AT&T had only about 3,800 reports around the same time, and only 7 percent were for no network or reception.
Verizon
Verizon had just over 8,600 reports on Downdetector; 78 percent were for "mobile phone."
Sprint
Sprint came in at just over 1,700 reports; 87 percent for phone service.
Disclosure: Downdetector is owned by Ookla, which is owned by Daxdi parent company Ziff Davis.
