Beneath the Internet: explosive growth drives improvements to the infrastructure

Functionally, the Internet is an interconnection of packet-switched networks based on the TCP/IP protocol suite. On a physical level, it is probably better visualized as a collection of service centers interconnected to a large extent by the same worldwide infrastructure that carries voice and every other kind of communications. That infrastructure has two distinct components: the long-haul trunks operated by long-distance service providers (also known as interexchange carriers, or IXCs), and the local loops (also known as subscriber loops and "last mile" connections) that radiate from local service providers to individual customers. The dominant technology in the long-haul plant is fiber optics, which has a truly enormous (and growing) communications capacity. The latest available technology allows a single optical fiber to transport between 1000 and 2000 gigabits of data per second. More advanced technologies will increase those numbers by about an order of magnitude within a year. The buzz is about optics and the long-haul plant, but the last mile is the part to watch with the development of optics, DSL and wireless technologies.