"Internet company" redirects here. For Internet-based companies, see Dot-com company.
"ISP" redirects here. For Internet-based companies, see Dot-com company.
"ISP" redirects here. For Internet-based companies, see Dot-com company.
"ISP" redirects here. For other uses, see ISP (disambiguation).
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An Internet service provider (abbr. ISP, also called Internet access provider or IAP) is a business or organization that provides consumers or businesses access to the Internet and related services. In the past, most ISPs were run by the phone companies. Now, ISPs can be started by just about any individual or group with sufficient money and expertise. In addition to Internet access via various technologies such as dial-up and DSL, they may provide a combination of services including Internet transit, domain name registration and hosting, web hosting, and colocation.
Contents
1 History
2 ISP connection options
3 How ISPs connect to the Internet
Just as their customers pay them for Internet access, ISPs themselves pay upstream ISPs for Internet access. In the simplest case, a single connection is established to an upstream ISP at multiple PoPs, or they may be customers of multiple upstream ISPs and have connections to each one at one or more of their PoPs. ISPs may engage in peering, where multiple ISPs interconnect with one another at a peering point or Internet exchange point (IX), allowing the routing of data between their networks, without charging one another for that data - data that would otherwise have passed through their upstream ISPs, incurring charges from the upstream ISP. ISPs that require no downstream and have only customers and/or peers, are called Tier 1 ISPs, indicating their status as ISPs at the top of the Internet beyond its own network; in turn,
