Widespread internet outages around the United States on Friday afternoon quelled productivity and sent irate customers to Twitter to complain. Comcast and Xfinity suffered the biggest service interruptions across its internet, cable, and landline products. The company, which has more than 29 million business and individual customers, said on Friday that the outages stemmed from fiber optic cables at two internet infrastructure companies that were cut or otherwise disrupted.  

Like virtually all internet providers, Comcast relies on a combination of its own fiber optic infrastructure and that of other partner companies to seamlessly route data around the world.