Good article discussing cable modems vs. ADSL
Several people have posted asking about the advantages and disadvantages of cable modems vs. ADSL. I thought that this article provides an excellent summary and analysis (naturally it is pro-ADSL).
The entire article can be found at
zdnet.com
THE CABLE ROUTE
With a cable Internet connection you can expect transfer speeds of up to 30Mbps.
Cable setup is inexpensive; you typically get the cable modem free when you sign up
for the service, which usually costs $50 per month or less.
Theoretically, cable is an option for anyone already wired for cable TV, as are most
urban and suburban homes in the United States. But your cable company has to set
itself up to provide cable modem service first. Only a few have done so due to the
expense, and those that have are still in the testing phase. More reality: Most of the test
sites offer a top download speed of 1.5Mbps and a top upload speed of 300Kbps.
And here's the big caveat--you have to share that bandwidth with your cable
neighbors. As the guy next door downloads an MPEG clip of the latest
Schwarzenegger movie, your download speeds plummet. Variable download speeds
mean you have to schedule your heavy downloads to avoid rush hours. Home users
might not mind the inconvenience, but businesses need something more stable.
ENTER DSL
That something is DSL. It's theoretically slower than cable, with download speeds
topping off around 9Mbps. But it's 20 times faster than satellite connections, 60 times
faster than ISDN, and 250 times faster than 33.6Kbps analog modems. Best of all,
those bits are squeezed through the same copper wire you use for phone calls, but
without the complex setup of ISDN. DSL does this by taking advantage of unused
frequencies that exist on standard telephone lines. While it creates channels for moving
data up and down the line, the original plain-old telephone service (POTS) frequencies
remain free to handle voice traffic. So you need only a single line for all your
telecommunications. And while its peak speeds may be slower than cable's, you don't
have to share the line with your bandwidth-hogging neighbors.
Right now the flavor of DSL that's available is called asymmetric DSL (ADSL).
Asymmetric indicates that the data moves more quickly downstream (from the
Internet) than upstream (to the Internet). ADSL uses special modems called endpoints.
Along with an endpoint, your PC needs a network interface card that treats the modem
like a local device on the network. Many ADSL modems combine both functions into
a single internal card. (See How ADSL Works.) Most of the major modem makers
are producing endpoints, including Hayes, Ericsson, Global Village, ParGain, and
3Com, but don't rush out to the store to buy one just yet. Many ADSL service
providers bundle the hardware you need with the service.
One of the most attractive things about ADSL is that it bypasses most of the public
switched telephone network (PSTN), the connection machine that often delays analog
modem and ISDN connections with busy signals, ring-no-answer calls, and other
reliability gremlins. Not using switches also means, in the long run, that monthly charges
for ADSL could be lower than for ISDN. Another plus: ADSL is a pure network
service, so unlike analog modems and ISDN adapters that must dial, connect, and
disconnect from the Net, the ADSL connection is always on. That doesn't just mean
saving a few seconds for each connection; it also means any ADSL subscriber can set
up Internet services available to others, such as Web sites and file archives.
These sketchy standards, goals, and costs might just remind you of ISDN's shaky
start, which made it an overhyped, overcharged, and underserviced technology. But
even with these uncertainties, the prospect of DSL is exciting. If all goes well, expect
ADSL to start taking over the business world by mid-1998. |
