CTL CenturyLink Inc

By Maria Armental 

Cable giant Comcast Corp. blamed cuts in two fiber lines for a widespread system failure that knocked out cable, internet and phone services around the country.

It was unclear how many customers were affected as the system failure, which appeared contained to Comcast's network, also disrupted connectivity services like Netflix Inc. and Okta Inc. as other internet service providers routed internet traffic through Comcast's network, according to network research firm ThousandEyes.

Comcast, one of the dominant telecom companies in the U.S. with more than 29 million business and residential customers, said most service had been restored late Friday.

The Philadelphia-based company, one of the dominant telecom companies in the U.S. with more than 29 million business and residential customers, said the lines damaged are owned by CenturyLink Inc. and Zayo Group Holdings Inc.

A spokeswoman for CenturyLink issued a statement saying CenturyLink's network was working normally, though the company had "experienced two isolated fiber cuts in North Carolina affecting some customers that in and of itself did not cause the issues experienced by other providers."

The spokeswoman, Francie Dudrey, didn't comment further. Attempts to reach Zayo were unsuccessful.

Fiber networks, which make up the backbone of the internet, transmit vast amounts of internet traffic, processing everything from online purchases to 911 calls.

Down Detector and Outage.Report, two websites that monitor the running of consumer-technology services, ranked the system failure as extreme and posted maps indicating large numbers of customers affected in the New York, Philadelphia and Washington, D.C., metro areas as well as San Francisco, Chicago and Denver. Reports of outages, according to the websites, spiked early Friday afternoon.

Some customers took to social media to discuss the outages, saying they were having trouble getting through the company's phones and online chats. Comcast, on Twitter, directed customers to an internal website that was at one point down as well, eliciting a second round of customer complaints.

Write to Maria Armental at maria.armental@wsj.com

(END) Dow Jones Newswires

June 29, 2018 19:16 ET (23:16 GMT)

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