FCC: Staff Report on T-Mobile Outage on June 15 2020

Sean Donelan sean at donelan.com
Thu Nov 12 17:35:38 UTC 2020

FCC Issues Staff Report On T-Mobile Outage


The outage was initially caused by an equipment failure and then 
exacerbated by a network routing misconfiguration that occurred when 
T-Mobile introduced a new router into its network. In addition, the outage 
was magnified by a software flaw in T-Mobile’s network that had been 
latent for months and interfered with customers’ ability to initiate or 
receive voice calls during the outage.

44. While fiber link failures are common, PSHSB finds that these steps, 
taken together, will reduce the likelihood that a fiber link failure could 
result in the recurrence of a similar event in TMobile’s network because 
traffic would be routed to an alternative path that could handle it. 
Moreover, if such an event recurred on T-Mobile’s network, it would not 
cause such a large service disruption because T-Mobile would have improved 
its networks’ ability to manage congestion in the case of a similar event
and would have increased network capacity to maintain the network in a 
working state even with an increased volume of traffic.

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