T-Mobile and Verizon's outage left some customers unable to contact other numbers, whereas others experienced persistent connection issues between calls. As per the report by The Verge, the outage started at around 2 in the afternoon during Cyber Monday. Meanwhile, DownDetector announced on Twitter that some users of T-Mobile have reported that their carrier has been experiencing some problems since 1:49 PM.

Link: T-Mobile, Verizon Outage Stops Some Users from Calling
via http://www.techtimes.com