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Traditional Modem Dial-up
Today's analog modems support a theoretical maximum data rate of 56
Kbps. This makes traditional dial-up the slowest form of Internet access available. When connected to the Internet, modems also tie up one's phone line so that voice calls cannot be made. Despite their limitations, traditional modems remain very popular because of their reliability, low cost, and widespread support from providers.
Integrated Services Digital Network (ISDN)
ISDN pioneered the idea of simultaneous voice and data support over ordinary telephone lines. With ISDN Internet access, customers enjoy data rates as high as 128 Kbps and the ability to make or receive calls on the same line (as with DSL, below). Providers have made ISDN almost as widely available as dial-up in recent years, but the cost of ISDN service remains comparatively high.
Digital Subscriber Line (DSL) and Cable
Fast growing in popularity, DSL and cable network services bring affordable high-speed Internet access to the home market. Both of these
broadband technologies suffer from limited service availability, usually confined to urban and suburban areas. On average, cable and DSL support data rates of several hundred Kbps with peak performance above 1 Mbps.
Leased Lines
For the ultimate in high-speed network access, dedicated Internet connections can be leased from some providers. These lines operate at speeds ranging from 1.5 Mbps (T1 connections) to 4.5 Mbps (T3 connections). A provider can subdivide T1 lines, producing multiple separate connections performing as low as 128 Kbps each, a practice sometimes seen in apartment buildings. Expensive but very fast!
Wireless Access Services
Wireless networking remains immature and least available of today's Internet access options. Yet, the mobility promised by wireless Internet technologies like satellite or microwave appeal to many. Wireless Internet service providers offer data
rates and pricing competitive with DSL, but they must contend with higher equipment costs and public perceptions that key security features are lacking.
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