The Internet is a loosely-organised collaboration of computer networks that voluntarily communicate and interconnect via open procedures and protocols defined by Internet Standards. The Internet Protocol Suite (TCP/IP) consists of the core communications protocols that are used by these computer networks to interconnect and become Interconnected Networks. During the development of TCP/IP (1974), Carl Sunshine, Vinton Cerf and Yogen Dalal coined the term 'Internet' in RFC 675. The most important protocol of the Internet Protocol Suite is the Internet Protocol (IP): it creates a datagram format and numbering (address) system that enables packet-switching networks to interconnect. No single individual is credited with inventing the Internet, but a small group of individuals, named the 'Internet Pioneers', are credited with designing the core technical architecture of the Internet in the 1970s and 1980s. While there have been other terms used to describe the Internet -- Cyberspace and the Information Superhighway -- the Internet is the name that has stuck. Some of the most important organizations that manage the development and use of the Internet are the Internet Society (ISOC), Internet Architecture Board (IAB), Internet Engineering Steering Group (IESG), Internet Engineering Task Force (IETF), Internet Research Steering Group (IRSG) and Internet Research Task Force (IRTF).
The early history of the Internet is mostly located in the United States of America: this is because the backbone computer networks that evolved into the Internet, and the open procedures and protocols developed for these networks, were located and funded by either: departments of the federal government of the United States; independent agencies of the United States federal government; or American nonprofit advocacy organizations.
ARPANET (Advanced Research Projects Agency Network) was one of the first 'wide area' computer networks and was one of the first computer networks to feature packet switching. Packet switching underpins how the Internet works and ARPANET is viewed as a forerunner to the Internet. ARPANET allowed the U.S. military, research laboratories and universities to connect, communicate and exchange data. The first successful message sent on ARPANET was "login" and it was transmitted by Charles S. Kline at 10:30pm on the 29th of October 1969. When ARPANET was launched it consisted of four nodes, with each node featuring an Interface Message Processor (IMP). The four nodes were located at: University of California, Los Angeles (UCLA) - (SDS Sigma 7 computer) (Sign EXtend software); Stanford Research Institute (SRI) - (SDS 940 computer) (NLS software); University of California, Santa Barbara (UCSB) - (IBM 360/75 computer) (OS/MVT software); and the University of Utah - (DEC PDP-10 computer) (TENEX software). The first authority created for ARPANET was the Network Information Center (NIC) and it was created to manage the assignment of hostnames. By 1973 ARPANET contained over 25 nodes in North America and had its first international nodes in Norway and England. ARPANET was slowly decommissioned from 1985 to 1989: due to the creation of NSFNET and the Federal Internet Exchange (FIX).
Due to the Mansfield Amendment of 1973, the Department of Defense was directed to no longer fund the development of science projects. ARPANET was split into a military and a research network, and the research network of ARPANET was slowly phased out from 1975 onwards. Due to the need for a wide area computer network for scientific research a new wide area computer network was funded by the National Science Foundation (NSF) in the mid-1980s. The network they created was NSFNET 'National Science Foundation Network'. The original NSFNET backbone consisted of six supercomputer locations, located at U.S. universities and research institutions, and used the TCP/IP protocol suite to connect and transport data across the network. The location of the original six supercomputers are as follows: Princeton University (John von Neumann Center); University of California, San Diego (Supercomputer Center); University of Illinois (National Center for Supercomputing Applications); Cornell University (Cornell Theory Center); University of Pittsburgh (Pittsburgh Supercomputing Center (PSC)) and National Center for Atmospheric Research (NCAR). By 1987-1991 the NSFNET backbone was connected to a variety of regional and federal computer networks. To name but a few: BARRNet (Bay Area Regional Research Network), ESnet (Energy Sciences Network), MichNet (Michigan Network), MIDnet (Midwest Network), MILNET (Military Network), NSN (NASA Science Network), NorthWestNet (North West Network), NYSERNet (New York State Education and Research Network), SESQUINET (Sesquicentennial Network), SURAnet (South Eastern Universities Research Association Network) and Westnet (West State Network). Due to the success and popularity of NSFNET (originally developed for non-commerical use) there began to be issues over commercial access to it, which eventually led to the U.S. government deciding that the Internet backbone network should evolve to consisting of autonomous commercial computer networks. In the early 1990s Network Access Points (NAPs) were created to replace the NSFNET backbone. NAPs exchanged data between commercial backbone networks. The four original NAPs were: Ameritech, MFS Datanet, Sprint, and Pacific Bell. Network Access Points were a strategic 'steppingstone' and were eventually replaced by Internet Exchange Points. NSFNET was decommissioned on the 30th of April 1995 and ushered in the Internet era of commercial networks.
The networks that formed the early Internet were as follows: Tier One: typically, long-distance international telecom companies who are viewed as 'backbone' networks; Tier Two: typically, large regional Internet Service Providers; and Tier Three: small ISPs who pay for upstream transit from Tier Two networks. Tier one, two and three networks create 'interconnect agreements' with one another: these agreements decide how data is transferred and routed on the Internet. There are two types of interconnect agreement: 1) Transit agreement: data transfer is charged; 2) Peering agreement: data transfer is free. Tier one networks tend to be telecom companies who own national and international fiber optic trunk lines. The data routes of the Internet are like the thoroughfares of a country: motorways are the primary route that cars travel upon, and likewise, tier one networks are the primary route that data travels upon the Internet. Tier one networks typically connect to the entirety of the Internet via peering agreements and do not pay for their access. Some recognised tier one networks are AT&T, Verizon, and Sprint. Tier two networks are networks that must pay for upstream transit of data (access to tier one networks). Tier two networks also use Internet Exchange Points (IXP) to reduce their upstream transit costs and faults, and to improve latency and bandwidth. Some examples of tier two networks are: BT, Deutsche Telekom and France Telecom. Finally, we have tier three networks: these networks pay for upstream data transit from tier two networks. Tier three networks can be standalone single-homed networks or can be multihomed networks. Multihoming is where a tier three network purchases upstream access from multiple tier two networks: this helps to improve the reliability of their service in the scenario of a (SPOF) single point of failure. Internet Service Providers and Internet Exchange Points (IXP) typically place their most important network equipment at colocation centre's: these are facilities that are secure and provide protection against a multitude of natural and man-made threats. In the UK, Telehouse (London) and Telecity (Manchester), are two of the most important colocation centre's in the UK.
The first UK node to connect to ARPANET was UCL (University College of London) at a speed of 9.6 Kbps. By 1975 the UCL link was being used by several Ministry of Defense (UK) installations and it was also used to test the development of TCP/IP in the mid-1970s. The testing involved sending data packets via radio from a car traveling across the Golden Gate Bridge in San Francisco to a terminal at the Royal Radar Establishment in Malvern. UCL scholars, Paal Spilling and Peter Kirstein, played an important role in the development of TCP/IP and Kirstein is sometimes referred to as a 'founding father of the European Internet'. In 1988 members of the CERN Networking Group were present at a meeting of the Coordinating Committee for Intercontinental Research Network (CCIRN). Vint Cerf encouraged these Europeans to create an organisation that would be responsible for allocating Internet IP blocks in Europe. The result was the creation of RIPE (Réseaux IP Européens). By the late 1980s more and more European networks, such as the European Network (EUnet), began to switch from X.25 protocol to TPC/IP. By 1991 TCP/IP became the dominant networking model when the EBONE (standing for European Backbone) consortium was established to transition European networks from OSI to IP. During this era Telehouse Europe was founded and opened the Telehouse Docklands datacentre in London. Telehouse Docklands became the primary hub for the Internet in the United Kingdom. Telehouse Europe has expanded across London and Europe and has described itself as a "Backbone for the Global Internet Network". The following Internet Exchange Points (IXP) have operated out of Telehouse Docklands: LINX, NAPAfrica, DECIX, FRANCE-IX, Packet Exchange, JP-IX, LIPEX, NYIIX, LAIIX and LONAP. Some of these IXP's have provided provide services for DNS root nameservers, such as for the k.root-servers.net.
The commercial organisations that sell access to the Internet in the UK are commonly referred to as Internet Service Providers. Customers who purchase access from ISPs are referred to as subscribers. Before 1988 the Internet was funded publicly and restricted commercial access. Therefore, most UK Internet Service Providers were founded in the early 1990s. The first UK ISP is usually claimed to be @TheWorld, who sold access in 1989. Some other early ISPs include: Compuserve, Earthlink, AOL, PSINet and UUNet, but these were headquartered in the United States of America. The first UK based ISPs were: Pipex (1990), Demon Internet (1992), ExNet (1992), Pavilion (1993), Zetnet (1994), Easynet (1994), and Flexnet (1995). These ISPs only offered dial-up access but were crucial in developing the current infrastructure of the UK's Internet. Pipex was involved in helping to develop the London Internet Exchange (LINX), operated one of the first transatlantic leased lines (64k), was one of the first commercial ISPs to connect to JANET (an important research IP network in the UK), and hosted the early BBC online services. The first UK ISP to come to national prominence was Freeserve (1998): founded by Dixons Group plc it was promoted on television, print media and Dixons electrical stores. Freeserve were the first UK ISP to offer Internet access without a monthly subscription fee. In the 1990s there was a wide selection of ISPs, but the service quality provided by them varied wildly, some quickly 'folded' and left subscribers stranded without access. By the noughties, smaller ISPs were being purchased by larger telecoms companies. For example, Pipex were purchased by Tiscali in 2007 and Tiscali were purchased by Carphone Warehouse in 2009. This evolution of smaller ISPs being 'eaten up' by competitors has resulted in there only being a handful of big ISPs. While smaller ISPs still exist, as do niche ISPs (Satellite and Radio), most ISP subscribers (roughly 20 million subscribers) are customers of the four big UK ISPs: BT (PlusNet, EE), Sky Broadband, Virgin Media and TalkTalk. Many ISPs do not own their own network infrastructure, but instead rent access from other operators. Most ISPs sell access on a monthly or annual contract and provide a limited or unlimited download limit (but contain a fair usage policy).
An alphabetical list of UK ISPs, valid as of 2019, included: Ai Networks, Air Broadband, Airband Community Internet, Airfibre, Alncom, Andrews & Arnold, Aquiss, Ask4, B4RN, B4B Networks, Badenoch Broadband, Beacon Broadband, Beeline Broadband, Big Blue Rocket, BitStreme, bigblu, Bluewave, Box Broadband, Breathe internet, Bridge Fibre Limited, Broadband Wherever, BT, Call27, Cambridge Fibre Networks, Cerberus Networks, CIX, CloudScape Connect, Community Fibre Limited, Conxdigital, Corespeed, Country Connect, County Broadband, Cyber Ware, Derbyshire Broadband, Direct Save Telecom, Distant Voice, EE, Elite Limited, Entanet, Exa Networks, Exascale, FastNet International, Fibrecast, FibreNest, FluidOne, Freedomsat, Freeola, Full Fibre, G.Network Communications, Gamma, Gigaclear, Glide, Gradwell, Grain, Green ISP, GreenNet, Herefordshire Community Network, Hyperoptic, Idaq Networks, idnet, I Need Broadband, Jibba Jabba, KCOM, Leetline, Lingen Community Broadband, Luminet, M12 Solutions, M247, Merula, Netservers, Notspot, Novatech Connect, NOW Broadband, Oakford Internet Services, Onebill Telecom, Onestream, OptaNet, Optify, Orbital Net, Origin Broadband, Pine Media, Post Office, PlusNet, Pulse8broadband, Purebroadband, Scotnet, SSE, Seethelight, Shell Energy Broadband, Shetland Telecom, Sky, Spectrum Internet, Speednet Scotland, Spitfire, Supanet, Surrey Hills Internet, SW Internet, TalkTalk, The Phone Coop, Toople, Trooli, UK Broadband, Unchained ISP, Uno, Village Networks, Vispa, Virgin Media, Vodafone UK, Wave Internet, Wessex Internet, Wifinity, WightFibre, WiSpire, XLN Telecom, York Data Services, and Zen Internet.
The following access technologies have been provided or are available.
Wireless
- Satellite: VSAT, TDMA, SCPC
- Mobile (mobile / cellular networks): 2G, 3G, 4G, 5G
- WiMax (fixed wireless): IEEE 802.16 (802.16/d)
- WiFi (fixed wireless): IEEE 802.11 (802.11a, 802.11b, 802.11g,
802.11n, 802.11ac, 802.11ac-2013, 802.11ad)
Wired (broadband)
- DSL (digital subscriber line): (ADSL , SDSL)
- Cable (cable television infrastructure etc): DOCSIS
- Fiber Optic: FTTC (fibre to the cabinet), FTTP ( fiber to the
premises), FTTB (fiber to the building), FTTH (fiber to the home)
- Leased line (private data line): T-1 (T1) and E-1 (E1)
- Broadband over Power Line (BPL): PoE, PDSL, PLN
Wired (narrowband)
- Dial-up: v.22, v.27, v.32, v.34, v.90, v.92
- Integrated Services Digital Network (ISDN)
Since the advent of the first commercial ISPs in the early 1990s a wide variety of technologies have been used to facilitate access to their networks. From 1990-1998 most Internet users connected to ISPs using wired narrowband technologies, sometimes referred to as a 'fixed internet service'. The most popular wired narrowband access technology was dialup: restricted to a download speed of 40-56 kbit/s, the dialup technology established an Internet connection by dialing a telephone number on the public switched telephone network (PSTN) and could not be used at the same time as the telephone. Another early wired narrowband access technology was the Integrated Services Digital Network (ISDN): ISDN was expensive and only marginally faster than dialup (64 kbit/s or 128 kbit/s), it was mostly used by medium-large business subscribers.
From 2000-2004 DSL broadband -- and to a lesser extent cable broadband -- slowly replaced narrowband technologies (dialup and ISDN) as the dominant access technology. Broadly speaking, broadband is a technology that is defined as supporting multiple signals, so that the telephone service can be used at the same time as the Internet connection. Described as always 'on' it provided a download speed that was at least ten times faster than dialup. Broadband is not a clearly defined term and the criteria that define a broadband Internet connection have changed. From 2000-2017 the most popular broadband access technology has been the digital subscriber line (DSL) service which includes the following DSL technologies: VDSL, ISDN, SDSL, HDSL and ADSL. DSL's weakness and strength are its reliance upon the standard copper line telephone network: that provides excellent accessibility but has a limited data capacity. The quality and speed of DSL is measured by signal to noise ratio (SNR), sync speed and line attenuation.
Due to its drawbacks -- data capacity and line quality over distance -- the DSL technology has slowly been replaced by fiber optic access technologies: fiber optic provides a faster speed and improved reliability when compared to any fixed wired technology. The fiber optic access technology is a glass/plastic cable that is superior to copper cable in a number of ways: it's more reliable; the cable has a longer lifespan; it carries more data; higher speed at a long distance (8km+); it does not corrode; electromagnetic interference does not occur; and it is resistant to crosstalk. Most developed countries have partially implemented a 'superfast' fiber optic infrastructure and most urban areas in the UK have access to a fiber optic network. How fiber optic networks are implemented varies: rarely are they "full fibre" and they're typically a hybrid mix of aluminum/copper/fibre systems. In 2012 the UK government formed an organisation called Broadband Delivery UK (BDUK) whose ambition was two-fold: 1) provide superfast broadband to 90% of homes in the UK; 2) universal access to standard broadband (download speed of 2Mbps).
While fiber optic is currently (2020) the pinnacle of fixed internet services, the advent of smartphones has resulted in mobile/wireless broadband technologies 'eating up' a greater share of the internet service market. While smartphones are not capable of accessing every service available on the Internet, their processing power is increasing and for many subscribers the smartphone has replaced the computer as the primary device to access the Internet. Early mobile/cellular telecommunications technologies (2G: GSM and CDPD) were restricted to a slow download speed of between 56kbits to 115 kbits, but the speed of current mobile access technologies (3G/4G/5G: UMTS, HSPA, HSPA+, IMT-2020) has increased massively: with download speeds of up to 100 mbits. Mobile broadband is not the only type of wireless Internet access, the other type is referred to as Fixed Wireless Access (FWA) and the companies who provide a FWA service are called: Wireless Internet Service Provider (WISP). FWA services use a frequency on the radio spectrum to provide Internet access and have been implemented in rural areas that are not covered by fixed broadband internet services. FWA technologies can be either: 1) wide area (4G and WiMax); 2) short area (hotspot) (WiFi). WISPs can use security technologies like WEP to ensure that only authorised persons can access their network.