Most ISDNs offered by the phone companies provide two lines, called B channels, one for voice and one for data. Even faster is ISDN's Primary Rate Interface, which provides 23 B channels, equivalent to a T1 line . In order to connect an ISDN line, you need a network terminator and an ISDN terminal adapter. Typically, the network terminator is built into the adapter which may also include an analog modem for switching between analog and digital. DSL uses already existing copper wires to send data at greater speeds.
Speeds vary depending on the distance between the customer and the telco central office.
Though bandwidths up to 9 Mbps could be achieved, long distances and poor line qualities may reduce the rate of data transfer. Because DSL lines keep you constantly connected to the Internet, it is important to follow certain safety guidelines . For an in-depth look at DSL, visit the Sunworld site . Find out how you can get Free DSL and whether it is worth it. As millions of homes already have cable, it seems a cable modem would be one of the best ways to access the Internet.