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[citation needed], 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 2000's.[3] 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 EM 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.
Tier 1 providers
The largest providers, known as tier 1 providers, have such comprehensive networks that they never need to purchase transit agreements from other providers. As of 2000 there were only five tier 1 providers in the telecommunications industry. These carriers included Cable & Wireless Worldwide, UUNet, Sprint, AT&T Corporation, and Genuity.
Verizon
As of 2010 however, Verizon has become "the world's most connected Internet backbone". Verizon has a very large Internet footprint that is present throughout the world due to its diverse customer base which includes small- and medium-size businesses, large corporations, and content providers. They have held this top spot for 11 of the past 12 years.[8] Verizon plans to increase backbone speeds in the United States to 100 gigabit per second (Gbit/s), which would make it the first company to do so. Some of the enhanced data speed routes can be seen in Chicago, New York City, and Minneapolis.
Link
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.
Tier 1 providers
The largest providers, known as tier 1 providers, have such comprehensive networks that they never need to purchase transit agreements from other providers. As of 2000 there were only five tier 1 providers in the telecommunications industry. These carriers included Cable & Wireless Worldwide, UUNet, Sprint, AT&T Corporation, and Genuity.
Verizon
As of 2010 however, Verizon has become "the world's most connected Internet backbone". Verizon has a very large Internet footprint that is present throughout the world due to its diverse customer base which includes small- and medium-size businesses, large corporations, and content providers. They have held this top spot for 11 of the past 12 years.[8] Verizon plans to increase backbone speeds in the United States to 100 gigabit per second (Gbit/s), which would make it the first company to do so. Some of the enhanced data speed routes can be seen in Chicago, New York City, and Minneapolis.
Link