According to the Calix "U.S. Rural Broadband Report," based on data from 45 rural U.S. communications service providers from October through December 2011, video streaming accounted for 67% of downstream Internet traffic and 13% of upstream traffic in the studied networks. The top 5% of subscribers in the rural U.S. networks studied used more than 100 GB of downstream traffic a month and accounted for approximately 50% of Internet traffic.Large content distribution networks (CDNs) such as Level3, Limelight, and Akamai -- which carry video content from sites like Netflix and YouTube -- accounted for 80% of all streamed video traffic. In terms of upstream traffic, business services generated the most, accounting for 53% of all upstream traffic.Service providers that offer Internet services exclusively over fiber access networks saw subscribers generate over 2.67 times more traffic than service providers that offered Internet services over copper-based networks.