Network Access Point (NAP)
Definition of Network Access Point (NAP) in The Network Encyclopedia.
What is NAP (Network Access Point)?
NAP stands for Network Access Point is a point at which sections of the Internet’s high-speed backbone are connected. Internet service providers (ISPs) are connected at Network Access Points (NAPs) so that they can exchange packets.
The backbone of the Internet actually consists of sections of high-speed fiber-optic cabling that are owned by different carriers (including AT&T, Sprint, and MCI WorldCom). NAPs are places at which these carriers interconnect their lines so that the Internet can function as a single entity. NAPs contain high-speed switching facilities for transferring traffic from one carrier’s lines to another’s.
The National Science Foundation originally established four different NAPs in Chicago, New York, San Francisco, and Washington, D.C., but with the growth of the Internet and the changing landscape of telecommunication carrier companies, more NAPs have been created. These include “MAE West” in San Jose and “MAE East” in Washington, D.C., both of which are operated by MCI WorldCom.
To lessen the traffic burden on the Internet’s backbone, major ISPs can connect their services directly to a NAP in the form of a “peering arrangement,” whereby traffic that needs to move between two ISPs connected to the same NAP can move directly from one ISP to the other instead of having to traverse the Internet’s backbone.
What is ISP (Internet Service Provider)?
ISP is a company that provides individual users and businesses with connectivity to the Internet. Internet service providers (ISPs) also provide clients with access to Internet services such as Web hosting, Simple Mail Transfer Protocol (SMTP) mail, Usenet newsgroups, Internet Relay Chat (IRC), and downloadable Internet software.
ISPs come in various shapes and sizes, from volunteer-run freenets to local, regional, and national service providers such as America Online. Many smaller ISPs, especially those that originated in a university environment, still use freely available software such as Linux, Apache’s Web server, and Sendmail for providing services to customers.
Larger ISPs often use a heterogeneous network in which Internet Information Services (IIS) and Microsoft Exchange Server play an essential role by providing core Web and mail services, as well as support for advanced Web and e-commerce applications for business and corporate clients.
百度百科上的解释
网络接入点（NAP，network access point）是几个主要的因特网互联的点中的一个，它把所有的网络接入提供商都捆绑在一起，这样在AT&T的波兰用户就能够访问位于弗罗里达迈阿密的Bell South用户的网站了。
定 义
(1)通达因特网主干线的点。
(2)因特网服务提供商(ISP)互相连接的点。