Network access point

The backbone networks interconnect with each other at a dozen or so sites around the United States (and other similar sites around the world). These points of interconnection are called Network Access Points (NAPs). The connection is by means of a switching computer which looks at each incoming packet to see where that packet should be routed next. This switching computer is called a "router.”

When several backbones agree to interconnect at a given point, the connection is, loosely speaking, between “peers” rather than hierarchical. Consequently it is common for the owning companies to agree to interconnect without charging each other any fees.