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Some will let you use a dial-up number, although that will tack extra fees on your hotel room bill. You're more likely to be able to choose between DSL or cable if you live in a large urban area like San Francisco or New York. People who hooked up the speedstream dsl modem to their Macintosh had no complaints whatsoever.
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How many mailboxes are they willing to provide? ADSL, or asymmetric DSL, works over an ordinary phone line by using frequencies above the voice band. If you aren't within 18,000 feet of your telephone company, you will not be able to get any type of DSL service at all.
DSL, or 'digital subscriber line', is that handy set of technologies that allows you to browse the internet at warp speed. This technology suddenly appeared in homes around the world during the 1990s. But where did it come from, and how exactly does it work? Let's find out.
Origin
Back in the 1980s, engineers were poking around for a way to get bits of information from one computer to another via telephone lines. They figured out a way to do this using already-installed telephone lines. Joseph Lechleider, an analyst at Bellcore, and John Cioffi, who founded the Amati engineering firm, came up with the mathematical analysis and circuits that make DSL possible.
Telephone companies initially weren't thrilled with DSL, because the technology gave customers the option of using their pre-existing phone line for internet service instead of having to pay for a second phone line. Prior to broadband, modems had to dial up to a service provider, so customers typically had two separate lines; one for the phone and one for the modem.
However, as more and more media-rich content became available on the internet phone companies joined the technology train. Today, many companies, like AT&T, market their own brand of DSL service. Eventually the telephone companies realized that DSL saved them money since it didn't require digging new trenches for additional phone wiring, as would be the case when installing fiber optic cables to provide the same broadband access.
How DSL Works
For more than one hundred years, telephone lines have consisted of a pair of copper wires running from a main trunk owned by the phone company to a consumer's house. Copper is great for being able to carry a wide range of frequencies. This range is also called its "bandwidth."
The frequency range of the human voice is from 300 to 3,400 Hz. The telephone companies liked limiting the bandwidth because it allowed them to bundle many wires together at a central location without having any distortion caused by overlapping frequencies.
That leaves a lot of unused bandwidth - more than a million HZ -- on the copper wire, and that's why engineers started looking at using it for DSL in the first place.
DSL also splits the digital signals being carried by the copper wire into upstream and downstream channels. Market studies showed that internet users download more content than they upload, or send. So DSL makes the downstream channel three to four times faster than the upstream channel.