Internet backbone 
High-speed transmission lines used by local and regional networks to interconnect. The elements of this infrastructure are provided by government agencies such as the National Science Foundation; telecommunication corporations such as AT&T, IBM, and MCI; and research and educational institutions in the United States and abroad. These data transmission lines carry Internet traffic around the world and connect at network access points, or nodes. Local ISPs connect to this backbone to provide users with access to the Internet.