Internet Backbone

The Internet backbone refers to the principal data routes between large, strategically interconnected networks and core routers on the Internet. These data routes are hosted by commercial, government, academic and other high-capacity network centers, the Internet exchange points and network access points, that interchange Internet traffic between the countries, continents and across the oceans of the world. Internet service providers (often Tier 1 networks) participate in Internet backbone exchange traffic by privately negotiated interconnection agreements, primarily governed by the principle of settlement-free peering.

The Internet backbone is a conglomeration of multiple, redundant networks owned by numerous companies. It is typically a fiber optic trunk line. The trunk line consists of many fiber optic cables bundled together to increase the capacity. The backbone is able to reroute traffic in case of a failure. The data speeds of backbone lines have changed with the times. In 1998, all of the United States backbone networks had utilized the slowest data rate of 45 Mbit/s. However the changing technologies allowed for 41 percent of backbones to have data rates of 2,488 Mbit/s or faster by the mid 2000s. Fiber-optic cables are the medium of choice for Internet backbone providers for many reasons. Fiber-optics allow for fast data speeds and large bandwidth; they suffer relatively little attenuation, allowing them to cover long distances with few repeaters; they are also immune to crosstalk and other forms of Electromagnetic interference which plague electrical transmission.

Because of the enormous overlap between long-distance telephone networks and backbone networks, the largest long-distance voice carriers such as AT&T Inc., MCI, Sprint, and CenturyLink also own some of the largest Internet backbone networks. These backbone providers sell their services to Internet service providers (ISPs).

Each ISP has its own contingency network and is equipped with an outsourced backup. These networks are intertwined and crisscrossed to create a redundant network. Many companies operate their own backbones, that are all interconnected at various Internet exchange points (IXPs) around the world. In order for data to navigate this web, it is necessary to have backbone routers, which are routers powerful enough to handle information on the Internet backbone and are capable of directing data to other routers in order to send it to its final destination. Without them, information would be lost because data does not know how to locate its end destination.

Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. Source: Wikipedia