The
Internet backbone refers to the principal data routes between large, strategically interconnected
networkA computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
s and
core routerA core router is a router designed to operate in the Internet backbone, or core. To fulfill this role, a router must be able to support multiple telecommunications interfaces of the highest speed in use in the core Internet and must be able to forward IP packets at full speed on all of them. It...
s in the
InternetThe Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
. These data routes are hosted by commercial, government, academic and other high-capacity network centers, the
Internet exchange pointAn Internet exchange point is a physical infrastructure through which Internet service providers exchange Internet traffic between their networks . IXPs reduce the portion of an ISP's traffic which must be delivered via their upstream transit providers, thereby reducing the average per-bit...
s and
network access pointA Network Access Point was a public network exchange facility where Internet Service Providers connected with one another in peering arrangements. The NAPs were a key component in the transition from the NSFNET era when many networks were government sponsored and commercial traffic was prohibited...
s, that interchange Internet traffic between the countries, continents and across the oceans of the world. Traffic interchange between the
Internet service providerAn Internet service provider is a company that provides access to the Internet. Access ISPs directly connect customers to the Internet using copper wires, wireless or fiber-optic connections. Hosting ISPs lease server space for smaller businesses and host other people servers...
s (often
Tier 1 networkA tier 1 network is an Internet Protocol network that participates in the Internet solely via settlement-free interconnection, also known as settlement-free peering.-Definition:...
s) participating in the Internet backbone exchange traffic by privately negotiated
interconnection agreementsAn interconnect agreement is a business contract between telecommunications organizations for the purpose of interconnecting their networks and exchanging telecommunications traffic...
, primarily governed by the principle of settlement-free
peeringIn computer networking, peering is a voluntary interconnection of administratively separate Internet networks for the purpose of exchanging traffic between the customers of each network. The pure definition of peering is settlement-free or "sender keeps all," meaning that neither party pays the...
.
History
The first high speed backbone was created by the
National Science FoundationThe National Science Foundation is a United States government agency that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National Institutes of Health...
in 1987. It was called the
NSFNETThe National Science Foundation Network was a program of coordinated, evolving projects sponsored by the National Science Foundation beginning in 1985 to promote advanced research and education networking in the United States...
, and was a T1 line that connected 170 smaller networks together. The following year,
IBMInternational Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
,
MCIMCI may refer to:* 1101 in Roman numerals*mCi, millicurie, 1/1000 of a curie, a non-SI unit of radioactivity*MCi, megacurie, 1,000,000 times a curie-Company:...
and
MeritThe term merit constitutes a desirable trait or ability belonging to a person or an object.It may refer to:* Merit * Merit * Meritocracymerit may also mean:...
would create a T3 backbone. In the early days of the internet, backbone providers exchanged their traffic at government sponsored
network access pointA Network Access Point was a public network exchange facility where Internet Service Providers connected with one another in peering arrangements. The NAPs were a key component in the transition from the NSFNET era when many networks were government sponsored and commercial traffic was prohibited...
s, until the government privatized the internet, and then transferred the NAPs to commercial providers.
Architectural principles
The Internet, and consequently its backbone networks, do not rely on central control or coordinating facilities, nor do they implement any global network policies. The
resilienceIn computer networking: “Resilience is the ability to provide and maintain an acceptable level of service in the face of faults and challenges to normal operation.”These services include:* supporting distributed processing* supporting networked storage...
of the Internet results from its principal architectural features, most notably the idea of placing as few network
stateIn computer science and automata theory, a state is a unique configuration of information in a program or machine. It is a concept that occasionally extends into some forms of systems programming such as lexers and parsers....
and control functions as possible in the network elements, but instead relying on the endpoints of communication to handle most of the processing to ensure data integrity, reliability, and authentication. In addition, the high degree of
redundancyIn engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe....
of today's network links and sophisticated real-time
routingRouting is the process of selecting paths in a network along which to send network traffic. Routing is performed for many kinds of networks, including the telephone network , electronic data networks , and transportation networks...
protocols provide alternate paths of communications for load balancing and congestion avoidance.
Infrastructure
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 2000's. The FCC currently defines "high speed" as any connection with data speeds that exceed 200 kilobits per second. An Azerbaijani based telecommunication company, Delta Telecom, has recently developed a very efficient trunk line with possible speeds of to 1.6 terabits per second. Internet traffic from this line goes through the countries of Iran, Iraq and Georgia.
Fiber-opticFiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber. The light forms an electromagnetic carrier wave that is modulated to carry information...
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
attenuationIn physics, attenuation is the gradual loss in intensity of any kind of flux through a medium. For instance, sunlight is attenuated by dark glasses, X-rays are attenuated by lead, and light and sound are attenuated by water.In electrical engineering and telecommunications, attenuation affects the...
, allowing them to cover long distances with few repeaters; they are also immune to crosstalk and other forms of
EM interferenceElectromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
which plague electrical transmission.
Modern backbone
Because of the enormous overlap between long distance telephone networks and the internet backbone networks, the largest long distance voice carriers such as
AT&TAT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
,
MCIMCI may refer to:* 1101 in Roman numerals*mCi, millicurie, 1/1000 of a curie, a non-SI unit of radioactivity*MCi, megacurie, 1,000,000 times a curie-Company:...
,
SprintSprint Nextel Corporation is an American telecommunications company based in Overland Park, Kansas. The company owns and operates Sprint, the third largest wireless telecommunications network in the United States, with 53.4 million customers, behind Verizon Wireless and AT&T Mobility...
and
CenturyLinkCenturyLink, Inc. is a United States telecommunications firm, headquartered in Monroe, Louisiana. The company, founded as Central Telephone & Electronics Corporation in 1968, later changed its name to Century Telephone Enterprises, Inc. in 1971, and then was called CenturyTel, Inc. from 1999 to 2010...
also own some of the largest internet backbone networks. These backbone providers will then sell their services to ISPs. Each ISP has its own contingency backbone network, and at the very least, 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 IXPs around the world. In order for data to navigate through this diverse web that the backbone creates, backbone routers are needed. These backbone routers are routers that are powerful enough to handle information on the internet backbone, and they direct data to other routers in order to send it to its final destination. Without these backbone routers, information would be lost since data would not know how to locate its end destination. The very largest providers, known as
Tier 1A tier 1 network is an Internet Protocol network that participates in the Internet solely via settlement-free interconnection, also known as settlement-free peering.-Definition:...
providers, have such comprehensive networks that they never need to purchase transit agreements from other providers. As of 2000 there were only five internet backbone providers at the Tier 1 level in the telecommunications industry. These carriers included Cable & Wireless Worldwide,
UUNetUUNET founded in 1987, was one of the largest Internet service providers and one of the nine Tier 1 networks. It was based in Northern Virginia and was the first commercial Internet service provider...
,
SprintSprint Nextel Corporation is an American telecommunications company based in Overland Park, Kansas. The company owns and operates Sprint, the third largest wireless telecommunications network in the United States, with 53.4 million customers, behind Verizon Wireless and AT&T Mobility...
,
AT&TAT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
and
GenuityGenuity is currently an umbrella brand from Monsanto to cover its genetically modified products. Previously, the name was used for a web hosting business owned by Bechtel, which was then sold to the ISP business under GTE in 1997 and spun off as an independent company in 2000...
. As of 2010 however, Verizon
http://www22.verizon.com/content/verizonglobalhome/ghp_landing.aspx has become "the world's most connected internet backbone." Verizon has a very large internet footprint that reaches all over the world due to their diverse customer base which includes small and medium size businesses, large corporations, content providers, and many more. They have held this top spot for 11 of the past 12 years. Verizon also plans to increase backbone speeds in the U.S to 100 Gbit/s, the first company to do so. Some of this enhanced data speed can be seen on routes from Chicago to New York and Minneapolis to Kansas City.
Peering agreements
Backbone providers of roughly equivalent market share regularly create agreements called peering agreements. These agreements allow the use of another's network to hand off traffic where it is ultimately delivered. They usually do not charge each other for this use as they all get revenue from their customers regardless.
Transit agreements
Backbone providers of unequal market share usually create agreements called
transit agreementsInternet transit is the service of allowing network traffic to cross or "transit" a computer network, usually used to connect a smaller Internet service provider to the larger Internet...
, and usually contain some type of monetary agreement.
Regulation
Antitrust authorities have acted to ensure that no provider grows large enough to dominate the backbone market. The FCC has also decided not to monitor the competitive aspects of the Internet Backbone interconnection relationships, as long as the market continues to function well without regulation.
Egypt
Egypt's government effectively shut down the backbones of the four major ISPs on January 27, 2011 at approximately 5:20pm EST. Evidently the backbones had not been physically cut, as the internet traffic that runs through Egypt, such as that from Europe to Asia, was unaffected. Instead, the government shut off the Border Gateway Protocol sessions. BGP sessions are responsible for the communication between different ISPs, and route traffic accordingly. They also broadcast the associated IP adressess to the other ISPs. When the government forced the ISPs to turn off their BGP sessions, they were effectively able to shut off the internet because the packets of data did not know where to go.
Only one of Egypt's ISPs was allowed to continue operations. The ISP Noor Group provided connectivity only to Egypt's stock exchange as well as some government ministries. Other ISPs started to offer free dial-up internet in other countries.
Europe
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
is a major contributor to the growth of the international backbone as well as a contributor to the growth of internet bandwidth. As of 2003, Europe is credited with 82 percent of the world's international cross border bandwidth. The company
Level 3 CommunicationsLevel 3 Communications is a telecommunications and Internet service provider headquartered in Broomfield, Colorado.It operates a Tier 1 network. The company provides core transport, IP, voice, video and content delivery for most of the medium to large Internet carriers in North America and Europe...
has begun to launch a line of dedicated internet access and
virtual private networkA virtual private network is a network that uses primarily public telecommunication infrastructure, such as the Internet, to provide remote offices or traveling users access to a central organizational network....
services which gives large companies direct access to the Tier 3 level backbone. Connecting companies directly to the backbone will allow enterprises faster internet service which meets a large market need. One European company developed an internet advancement that was an innovative way to utilize the backbone and provide internet access to mobile users. This advancement allowed users to access broadband internet on a high speed train that travels to cities such as Paris and Amsterdam while moving at speeds of up to 300 km/h. The connectivity worked by having internet cables on the train connect to a satellite modem on top of the train. This satellite modem then establishes a connection with a satellite in space which is connected to the internet backbone. The users then set up a connection between their device and the train’s internet cables to have access to the internet. Certain countries in Europe have very simple backbone networks. One example showing this was when a woman pierced a fiber backbone line with a shovel and left all of
ArmeniaArmenia , officially the Republic of Armenia , is a landlocked mountainous country in the Caucasus region of Eurasia...
without internet access for 12 hours.
India
India's backbone is very extensive due to a very large population. This country alone has nearly 250 million internet users as of 2009. Four of India's top Internet Service Providers are Tata Communications, BSNL, MTNL, and Reliance Communications. Tata Communications is a Tier-1 IP network, with connectivity to more than 200 countries across 400 PoPs and nearly 1,000,000 square feet (93,000 m2) of data center and colocation space worldwide. It is India's largest provider in data center services and also operates India's largest data center in Pune. The backbone structure keeps on getting stronger because of the huge number of new emerging mobile operators which leads to decrease in prices due to competition in the market.
Japan
Japan's internet backbone needs to be very efficient due to the high demand for the internet and technology in general. Japan had over 86 million internet users in 2009, and it is projected to climb to nearly 91 million internet users by 2015. Since Japan has a demand for fiber to the home, Japan is looking into tapping off of a fiber-optic backbone line of NTT, a domestic backbone carrier, in order to deliver this service at cheaper prices.
See also
- Trunking
In modern communications, trunking is a concept by which a communications system can provide network access to many clients by sharing a set of lines or frequencies instead of providing them individually. This is analogous to the structure of a tree with one trunk and many branches. Examples of...
- Switching
LAN switching is a form of packet switching used in local area networks. Switching technologies are crucial to network design, as they allow traffic to be sent only where it is needed in most cases, using fast, hardware-based methods.- Layer 2 switching :...
- Routing
Routing is the process of selecting paths in a network along which to send network traffic. Routing is performed for many kinds of networks, including the telephone network , electronic data networks , and transportation networks...
- Backbone network
A backbone network or network backbone is a part of computer network infrastructure that interconnects various pieces of network, providing a path for the exchange of information between different LANs or subnetworks. A backbone can tie together diverse networks in the same building, in different...
- Network service provider
A network service provider is a business or organization that sells bandwidth or network access by providing direct backbone access to the Internet and usually access to its network access points...
- Mbone
Mbone was an experimental backbone for IP multicast traffic across the Internet developed in the early 1990s. It required specialized hardware and software...
- Internet2
Internet2 is an advanced not-for-profit US networking consortium led by members from the research and education communities, industry, and government....
- Default-free zone
In the context of Internet routing, the default-free zone refers to the collection of all Internet autonomous systems that do not require a default route to route a packet to any destination...
- Collapsed backbone
A collapsed backbone is a type of backbone network architecture.The traditional backbone network goes over the globe to provide interconnectivity to the remote hubs. In most cases, the backbones are the links while the switching or routing functions are done by the equipments at each hub...
- Parallel backbone
There are a few different types of backbones that are used for an enterprise-wide network. When organizations are looking for a very strong and trustworthy backbone they should chose a parallel backbone. This backbone is a variation of a collapsed backbone in that it uses a central node...
- Distributed backbone
A distributed backbone is a backbone network that consists of a number of connectivity devices connected to a series of central connectivity devices, such as hubs, switches, or routers, in a hierarchy...
- Serial backbone
A serial backbone is the simplest kind of backbone network. Serial backbones consist of two or more internet working devices connected to each other by a single cable in a daisy-chain fashion. A daisy chain is a group of connectivity devices linked together in a serial fashion. Hubs are often...
External links