> It seems to me that dialup and DSL would be analagous to two ways of
> yelling across a field; like two ways of yelling, DSL and dialup use
> the same medium.
A very simple analogy might be yelling, then using a megaphone
to yell. The megaphone doesn't "amplify" your voice, but directs
it a little better so it can be heard further.
Adding this analogy, imagine yelling across a field crowded with
people talking as opposed yelling across an empty field. The speech
of the other people will interfere with your yelling.
Another analogy might be signalling across a field using colored
flags. In all cases you are using reflected light. But the ability
to see the distant flag will vary based on the color of the flag. A
person holding a green flag standing in front of trees will be
difficult to discern compared to someone holding an orange flag. The
_carrier_ of your signal--the reflected color of the flag, is
different and different carriers are more efficient.
Let's note that the limitation isn't just in the plain copper wire
that comes out of your telephone. There's also a limitation in the
telephone company facilities. A voice conversation doesn't need much
"room" (bandwidth) to be clearly understood. (Notice if you play
music over a telephone that sounds terrible at the other end -- that's
because the phone doesn't have the bandwidth for the more complex
sounds of music compared to voice). Anyway, the telephone company has
your voice share space with other voices. While this is fine for
voice, it limits data transmission to 56K.
> Between the CO and the customer, isn't voice service just bare wire?
> Are there inline amps? If so, they could preemphasize high
That varies tremendously from customer to customer.
> I don't understand what kind of signal dsl uses to carry so much more
> data than dialup without needing broadband cable.
It uses digital. Crisp, to the point. As mentioned above, an orange
flag transmits 'better' than a green flag. Both are using the same
medium. Digital transmits better and can make better use of a pair of
> If you have a second phone line for your modem, a $25 ISP, Direct TV,
> and perhaps other Bellsouth services, they will give you a price where
> going to DSL will lower your costs. However, for somebody whose only
> cost is $100 a year for an ISP, DSL would add $500 to his annual
> budget. Many feel they can't afford it, just as farmers before the
> Model T felt that they had no choice but to stick with slow,
> inconvenient horses and wagons.
AFAIK, if you get DSL, you no longer need a second phone line and
everything can come over your DSL line. That is, you can talk on the
phone and use the computer at the same time, and get faster computer
The pricing of services is a function of marketing, not technology.
A consumer has to choose the best price/service suited to their needs.
Sometimes a bundled package may end up still cheaper than a la carte.
> You say internet costs depend on how much traffic you have.
That's not really accurate. Internet costs whatever you want it to
cost. If need your response RIGHT NOW, you should get a higher speed
connection. If you're doing a lot of work and don't like the long
waits, you should get a higher speed connection. If you don't mind
slow response time, you can make do as is. Plenty of people do.
There are even higher speed connections than DSL, although at some
point you're limited by the overall Internet traffic and the response
time of remote sites. Indeed, often times what appears as slow
connections is actually not related to your own connection, but at
intermediate or distant ends.
> I think there's a big untapped market for DSL, and it could be
> profitable at a low price. Cadillac did not introduce the Model T,
> and I guess Bellsouth doesn't want to offer existing customers
> something cheaper.
What is being offered is changing rapidly as technologies change and
new equipment is installed. Many cable companies offer service over
their lines as well in competition with Bell companies. Some Bell
companies are offering "FIOS" which is extra high speed.
Some of us whose modems keep getting fried by lightning are making
do with 14.4.