How four rotten packets broke CenturyLink's network for 37 hours, knackering 911 calls, VoIP, broadband

A handful of bad network packets triggered a massive chain reaction that crippled the entire network of US telco CenturyLink for roughly a day and a half. This is according to the FCC's official probe [PDF] into the December 2018 super-outage, during which CenturyLink's broadband internet and VoIP services fell over and stayed down for a total of 37 hours. This meant subscribers couldn't, among other things, call 911 over VoIP at the time – which is a violation of FCC rules, and triggered a formal investigation.
Read more: https://www.theregister.co.uk/2019/08/20/centurylink_outage_report_fcc/?source=Snapzu