T-Mobile says its massive outage on Monday was caused by failures of a leased third-party fiber circuit and its backup that resulted in an "IP traffic storm" (Sean Hollister/The Verge)

Sean Hollister / The Verge:
T-Mobile says its massive outage on Monday was caused by failures of a leased third-party fiber circuit and its backup that resulted in an “IP traffic storm”  —  “We did not meet our own bar for excellence,” writes T-Mobile's CTO  —  If you've been wondering what could knock …