Updated T-Mobile US is suffering a nationwide technical breakdown, preventing customers from receiving calls and knackering data connections.
We understand not only are incoming calls being black-holed, but some subscribers saw their connectivity downgraded from LTE to HSPDA when trying to make calls, and encountered busy circuit errors. Other punters said they were able to make outgoing calls and send texts, but not receive anything. T-Mobile US, which is merging with Sprint, acknowledged voice and data services were hit today.
The hours-long outage started around midday Pacific Time (1900 UTC), according to Down Detector. It appears complaints from the self-styled un-carrier's subscribers are tailing off, at time of writing, suggesting some voice and data services are being slowly restored to normal.
A couple of hours ago, T-mob's president of technology Neville Ray tweeted: "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."
And about half an hour ago, he updated us all with:
Teams continue to work as quickly as possible to fix the voice and messaging problems some are seeing.
Data services are now available and some calls are completing. Alternate services like WhatsApp, Signal, iMessage, Facetime etc. are available. Thanks for your patience.
Interesting that the tech boss is suggesting folks use over-the-top apps rather than the cellular network's own offerings. There were reports that other carriers – such as Verizon and AT&T – were also suffering downtime, though they denied anything was amiss with their networks. ®
Updated to add at 0330 UTC, June 16
There still appears to be lingering connectivity problems for T-Mobile US, though the number of complaints on Down Detector continue to fall. Ray told folks on Twitter in the past hour: "My team is working hard to fix it and I will let you know as soon as the issue is resolved. Thank you for your patience."
Updated to add at 0300 UTC, June 17
T-Mobile US has blamed a fiber cut, and lack of working redundancy, for its outage. Its network became overloaded and fell over:
The trigger event is known to be a leased fiber circuit failure from a third party provider in the Southeast. This is something that happens on every mobile network, so we’ve worked with our vendors to build redundancy and resiliency to make sure that these types of circuit failures don’t affect customers. This redundancy failed us and resulted in an overload situation that was then compounded by other factors. This overload resulted in an IP traffic storm that spread from the Southeast to create significant capacity issues across the IMS (IP multimedia Subsystem) core network that supports VoLTE calls.