Comcast Corp. has embarked on a plan to extend its national fiber backbone and has tapped Level 3 Communications to help it get the job done.

The backbone will be primarily based on 20-year dark-fiber from Level 3 and other sources. Comcast said it has agreements in place to cover more than 19,000 route miles – enough to cover 95 percent of its national footprint. The MSO expects the network to involve $100 million of capital, when fiber, fiber capacity, routing and optical gear are factored in.

With potential capacity at almost 3 terabits per second, Comcast’s backbone will serve as a pipeline for a wide range of bandwidth-intensive services. The MSO initially will provision the network with multiple 10 Gbps wavelengths, each capable of delivering almost 3,000 video channels.

“This agreement with Level 3 will further enhance our ability to deliver new and innovative services such as video-on-demand, high definition television, digital video recorders, high-speed Internet access and advanced voice services,” said Dave Fellows, Comcast’s executive vice president and chief technology officer.