Cogent Communications, which provides Internet backbone services to large companies and Internet service providers, experienced an outage caused by a routing instability at around 9:30 AM east coast time on Thursday, the company said.
The problem affected approximately 10 percent of Cogent's customers, which include Internet service providers such as Time Warner Cable. As of 2 pm on Thursday, network service was restored for most customers, the company said.
Back in October, some Cogent customers experienced problems when Level 3 Communications, another Internet backbone service provider, cut off its direct "peering" connections to Cogent.
The situation arose from a breakdown in a so-called peering arrangement, in which companies of similar sizes agree to exchange data traffic across their networks without compensation. Level 3 had argued that it is larger than Cogent, so a free peering relationship is no longer appropriate. It had asked Cogent to start paying for the connection, but Cogent refused saying that it is comparable in size to Level 3.
The companies eventually reached an agreement on their contract, but not after thousands of customers experienced major disruptions in service for several days.