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An Internet service provider (ISP) is an organization that provides access to the Internet.

Internet service providers can be either community-owned and non-profit, or privately owned and for-profit.

Access ISPs directly connect clients to the Internet using copper wires, wireless or fiber-optic connections.^[1] Hosting ISPs lease server space for smaller businesses and other people (colocation). Transit ISPs provide large amounts of bandwidth for connecting hosting ISPs to access ISPs.^[2]

Internet connectivity options from end-user to Tier 3/2 ISPs

History[link]

The Internet started off as a closed network between government research laboratories and relevant parts of universities. As it became more popular, universities and colleges started giving more of their members access to it. As a result of its popularity, commercial Internet service providers sprang up to offer access to the Internet to anyone willing to pay for the service, mainly to those who missed their university accounts. In 1990, Brookline, Massachusetts-based The World became the first commercial ISP.^[3]

Classification[link]

Access providers[link]

ISPs employ a range of technologies to enable consumers to connect to their network.^{[citation needed]}

For users and small businesses, traditional options include: dial-up, DSL (typically Asymmetric Digital Subscriber Line, ADSL), broadband wireless, cable modem, fiber to the premises (FTTH), and Integrated Services Digital Network (ISDN) (typically basic rate interface).^{[citation needed]}

For customers with more demanding requirements, such as medium-to-large businesses, or other ISPs, DSL (often Single-Pair High-speed Digital Subscriber Line or ADSL), Ethernet, Metropolitan Ethernet, Gigabit Ethernet, Frame Relay, ISDN (B.R.I. or P.R.I.), ATM (Asynchronous Transfer Mode) and upload satellite Internet access. Sync-optical cabling (SONET) are more likely to be used.^{[citation needed]}

Many access providers also provide hosting and email services.^{[citation needed]}

Hosting ISPs[link]

Hosting ISPs routinely provide email, FTP, and web-hosting services. Other services include virtual machines, clouds, or entire physical servers where customers can run their own custom software.^{[citation needed]}

Transit ISPs[link]

Just as their customers pay them for Internet access, ISPs themselves pay upstream ISPs for Internet access. An upstream ISP usually has a larger network than the contracting ISP and/or is able to provide the contracting ISP with access to parts of the Internet the contracting ISP by itself has no access to.^{[citation needed]}

In the simplest case, a single connection is established to an upstream ISP and is used to transmit data to or from areas of the Internet beyond the home network; this mode of interconnection is often cascaded multiple times until reaching a Tier 1 carrier. In reality, the situation is often more complex. ISPs with more than one point of presence (PoP) may have separate connections to an upstream ISP at multiple PoPs, or they may be customers of multiple upstream ISPs and may have connections to each one of them at one or more point of presence.^{[citation needed]}

Virtual ISPs[link]

A Virtual ISP (VISP) is an operation which purchases services from another ISP (sometimes called a "wholesale ISP" in this context)^[4] which allow the VISP's customers to access the Internet using services and infrastructure owned and operated by the wholesale ISP.

Free ISPs[link]

Free ISPs are Internet Service Providers (ISPs) which provide service free of charge. Many free ISPs display advertisements while the user is connected; like commercial television, in a sense they are selling the users' attention to the advertiser. Other free ISPs, often called freenets, are run on a nonprofit basis, usually with volunteer staff.^{[citation needed]}

Peering[link]

ISPs may engage in peering, where multiple ISPs interconnect at peering points or Internet exchange points (IXs), allowing routing of data between each network, without charging one another for the data transmitted—data that would otherwise have passed through a third upstream ISP, incurring charges from the upstream ISP.^{[citation needed]}

ISPs requiring no upstream and having only customers (end customers and/or peer ISPs) are called Tier 1 ISPs.^{[citation needed]}

Network hardware, software and specifications, as well as the expertise of network management personnel are important in ensuring that data follows the most efficient route, and upstream connections work reliably. A tradeoff between cost and efficiency is possible.^{[citation needed]}

Law enforcement/intelligence assistance[link]

Internet service providers in many countries are legally required (e.g. CALEA in the U.S.) to allow law enforcement and intelligence agencies to monitor some or all of the information transmitted by the ISP. Modern ISPs integrate a wide array of surveillance and packet sniffing equipment into their networks, which then feeds the data to law-enforcement/intelligence networks and software such as DCSNet in the United States, or SORM in Russia, allowing them to monitor Internet traffic in real time.^{[citation needed]}

See also[link]

• Broadband Internet access
• Broadband wireless access
• Cable Internet
• Communications Assistance for Law Enforcement Act
• Dial-up
• DSL
• Federation of Internet Solution Providers of the Americas (FISPA)
• Free-net
• IP address
• Internet backbone
• Internet Provider Security
• ISDN
• Leased line
• Modem
• Network access point
• Second-level ISP
  • Web hosting service
• Wireless internet service provider
• Category:Internet service providers

References[link]

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2007)

v t e Telecommunications (general) History Beacons Broadcasting Communications satellites Computer networks Drums Electrical telegraphs Fax Heliographs Hydraulic telegraphs Internet Mass media Mobile phones Optical telegraphy Photophones Radio Radiotelephones Telegraphy Telephones The Telephone Cases Television Undersea telegraph lines Videophones Pioneers Edwin Howard Armstrong John Logie Baird Alexander Graham Bell Tim Berners-Lee Jagadish Chandra Bose Vint Cerf Claude Chappe Lee De Forest Philo Farnsworth Reginald Fessenden Elisha Gray Guglielmo Marconi Alexander Stepanovich Popov Johann Philipp Reis Nikola Tesla Alfred Vail Charles Wheatstone Vladimir K. Zworykin Media Coaxial cable Free-space optical Optical fiber Radio waves Telephone lines Terrestrial microwave Networks ARPANET BITNET Ethernet FidoNet ISDN Internet Local area Mobile NGN Packet switched Public Switched Telephone Radio Television Telex Wide area World Wide Web Wireless Geographic v t e Telecommunications in Africa Sovereign states Algeria Angola Benin Botswana Burkina Faso Burundi Cameroon Cape Verde Central African Republic Chad Comoros Democratic Republic of the Congo Republic of the Congo Côte d'Ivoire (Ivory Coast) Djibouti Egypt Equatorial Guinea Eritrea Ethiopia Gabon The Gambia Ghana Guinea Guinea-Bissau Kenya Lesotho Liberia Libya Madagascar Malawi Mali Mauritania Mauritius Morocco Mozambique Namibia Niger Nigeria Rwanda São Tomé and Príncipe Senegal Seychelles Sierra Leone Somalia South Africa South Sudan Sudan Swaziland Tanzania Togo Tunisia Uganda Zambia Zimbabwe States with limited recognition Azawad Sahrawi Arab Democratic Republic Somaliland Dependencies and other territories Canary Islands / Ceuta / Melilla / Plazas de soberanía (Spain) Madeira (Portugal) Mayotte / Réunion (France) Saint Helena / Ascension Island / Tristan da Cunha (United Kingdom) Western Sahara v t e Telecommunications in Asia Sovereign states Afghanistan Armenia Azerbaijan Bahrain Bangladesh Bhutan Brunei Burma (Myanmar) Cambodia People's Republic of China Cyprus East Timor (Timor-Leste) Egypt Georgia India Indonesia Iran Iraq Israel Japan Jordan Kazakhstan North Korea South Korea Kuwait Kyrgyzstan Laos Lebanon Malaysia Maldives Mongolia Nepal Oman Pakistan Philippines Qatar Russia Saudi Arabia Singapore Sri Lanka Syria Tajikistan Thailand Turkey Turkmenistan United Arab Emirates Uzbekistan Vietnam Yemen States with limited recognition Abkhazia Nagorno-Karabakh Northern Cyprus Palestine Republic of China (Taiwan) South Ossetia Dependencies and other territories British Indian Ocean Territory Christmas Island Cocos (Keeling) Islands Hong Kong Macau v t e Telecommunications in Europe Sovereign states Albania Andorra Armenia Austria Azerbaijan Belarus Belgium Bosnia and Herzegovina Bulgaria Croatia Cyprus Czech Republic Denmark Estonia Finland France Georgia Germany Greece Hungary Iceland Ireland Italy Kazakhstan Latvia Liechtenstein Lithuania Luxembourg Macedonia Malta Moldova Monaco Montenegro Netherlands Norway Poland Portugal Romania Russia San Marino Serbia Slovakia Slovenia Spain Sweden Switzerland Turkey Ukraine United Kingdom England Northern Ireland Scotland Wales States with limited recognition Abkhazia Kosovo Nagorno-Karabakh Northern Cyprus South Ossetia Transnistria Dependencies and other territories Åland Faroe Islands Gibraltar Guernsey Jersey Isle of Man Svalbard Other entities European Union v t e Telecommunications in North America Sovereign states Antigua and Barbuda Bahamas Barbados Belize Canada Costa Rica Cuba Dominica Dominican Republic El Salvador Grenada Guatemala Haiti Honduras Jamaica Mexico Nicaragua Panama Saint Kitts and Nevis Saint Lucia Saint Vincent and the Grenadines Trinidad and Tobago United States Dependencies and other territories Anguilla Aruba Bermuda Bonaire British Virgin Islands Cayman Islands Curaçao Greenland Guadeloupe Martinique Montserrat Navassa Island Puerto Rico Saint Barthélemy Saint Martin Saint Pierre and Miquelon Saba Sint Eustatius Sint Maarten Turks and Caicos Islands United States Virgin Islands v t e Telecommunications in Oceania Sovereign states Australia East Timor (Timor-Leste) Fiji Indonesia Kiribati Marshall Islands Federated States of Micronesia Nauru New Zealand Palau Papua New Guinea Samoa Solomon Islands Tonga Tuvalu Vanuatu Dependencies and other territories American Samoa Christmas Island Cocos (Keeling) Islands Cook Islands Easter Island French Polynesia Guam Hawaii New Caledonia Niue Norfolk Island Northern Mariana Islands Pitcairn Islands Tokelau Wallis and Futuna v t e Telecommunications in South America Sovereign states Argentina Bolivia Brazil Chile Colombia Ecuador Guyana Paraguay Peru Suriname Uruguay Venezuela Dependencies and other territories Aruba Bonaire Curaçao Falkland Islands French Guiana South Georgia and the South Sandwich Islands