Running Linux, 5th Edition

ADSL

The 64-Kbps rate that ISDN supports is nice, but if you want to access multimedia files via the Internet or simply are using the Internet a lot, you may want even more bandwidth. Without drawing additional cables to your house or office, ADSL (Asynchronous Digital Subscriber Line), a variant of DSL (Digital Subscriber Line), is a convenient alternative that gives you up to 128 times (depending on your provider and your type of subscription) the bandwidth of standard dial-up access and is run via your ordinary telephone line. A drawback with ADSL is that it only works within a distance of about 5 to 8 kilometers (3 to 5 miles), depending on cable quality around the next switching station, which makes this service unavailable in rural areas. Typical bandwidths are 0.5 to 8 Mbps (megabits per second) downstream (to your computer—download operations, including viewing web pages and retrieving email) and 0.125 to 1 Mbps upstream (from your computer—upload operations, including sending email). Note that there are other technologies with similar-sounding names, such as SDSL. Although these are fundamentally different on the wire level, setting them up on your Linux box should be no different from ADSL.

ADSL is not dial-up access; once you have logged into your account, you are always connected. Some providers cut your connection after a while (often after 24 hours), upon which you have to log in again in order to regain access.^[*]

As we have already mentioned, there are no such ...