12 - Internet access

Abstract

Publisher Summary This chapter explains how a user can connect his/her PC to Internet or other networks using different options. Connection to the Internet backbone is supplied by “primary” Internet service providers (ISPs). ISPs outside of the USA are connected to the US Internet backbone as well as to ISPs on other continents through high-speed undersea (fiber optic) and satellite connections with a bandwidth of several tens or even hundreds of Megabits per second. These ISPs also own the servers needed for functions such as user authentication, mail (POP3 and SMTP) and domain name system (DNS) services. Users can subscribe to, and directly access these ISPs. There is also a proliferation of “secondary” ISPs differing from the others in that they do not own their own international access, but lease it from the primary ISPs. The ISPs supply the points through which the Internet can be accessed (the so-called points of presence) either on a regional or national level. This chapter explains how to connect a home PC to the Internet using dial-up facilities, or connect PC to the office LAN using a PPP server. It also describes connecting a LAN (small or large) to the Internet using either a proxy server, NAT machine, IP sharer, Unix/NT gateway, or a dedicated IP router.