Internet Service Provider (ISP)
A company that provides Internet access via subscription. Individuals or businesses can become subscribers. According to Jack Rickard, publisher of Boardwatch Magazine, ISPs operate on the Internet’s fourth or lowest level. Regional providers aggregate traffic from lower-order ISPs to the second, backbone level at the third level. The NAP (Network Access Point) is the highest level in North America, serving as peer-to-peer interconnection points for the largest backbones. There are three “official” NAPs: one in San Francisco, one in Chicago, and one in Pennsauken, New Jersey. ISPs use Internet routers, servers, and Rrack-mounted modems to provide a variety of services such as website hosting, FTP service, e-mail accounts, unified messaging, audio and video broadcasting, and, in some cases, Internet telephony and fax gateway services.