DSL or Cable:
by Adam Erickson
You're well aware of the
problem, of course: You spend 20 minutes trying to connect to the
Internet. You have time to go make (and then drink) a pot of coffee while
waiting for a Web page to display. You've given up altogether on
downloading the latest music because by the time you get a song
downloaded, the band has broken up (or possibly retired).
If all of this sounds
familiar, this article is for you. Read on to learn about high-speed DSL
(Digital Subscriber Line) and cable connections as practical alternatives
to the frustrating world of dial-up. We'll tell you what you need to know
to choose the right connection for your needs, and once you've made your
choice, we'll tell you how to get hooked up.
You already know that the Internet is painfully slow on a dial-up
connection, and one prescription for your pain is DSL. But exactly what is
DSL, and in what ways is it different from a regular phone line?
A standard telephone line is
referred to by telephone companies as POTS (Plain Old Telephone Service).
This POTS line is an analog line that can carry a limited amount of voice
or data traffic. This limit is evident to anyone who has a 56K (56Kbps, or
kilobits per second) modem, because such modems usually connect at an
actual maximum speed of between 40 Kbps and 48Kbps. DSL uses your existing
copper telephone wires to deliver high-speed Internet access. When you
sign up for DSL, your local phone company changes your POTS line to a
digital line. A digital line permits for data rates of 5Mbps (megabits per
second) or higher, over the same wires that used to top out at 40 to
49Kbps. However, data rates in the megabit range are unusual (and
expensive). Instead, most residential DSL customers will receive data
rates of roughly 384Kbps. (Still, 384Kbps is at least 10 times the speed
you're currently getting with your 56K modem.)
A DSL connection requires that a router be connected to the phone line in
your home. The router has an IP (Internet protocol) address, which, just
like your home postal address, tells others (in this case, other
computers) where to find you. Because the router is always connected to
your computer, as long as both the computer and router are turned on,
you're always connected to the Internet. This is different from a dial-up
scenario; in that case, you temporarily use the IP address of whichever
computer your modem connects to at your ISP (Internet service provider).
Another important feature of
DSL is the data rate you pay for is exactly what you get. If you sign up
for DSL at 384Kbps, your line is allocated exactly 384Kbps. Other factors,
such as the quality of the phone lines between your computer and your ISP,
can sometimes degrade the connection, but the bandwidth you pay for is
yours and yours alone. This is different from cable Internet connections,
which we'll discuss next.
Cable Internet access is another high-speed option in which, as you've
probably guessed, your local cable company uses your cable television
wires instead of a phone line to connect you to the Internet.
You may wonder how this is
possible. We're all accustomed to using the phone to talk from person to
person, so it's not hard to understand that a computer could talk to
another computer over a phone line. But how can a computer talk to other
computers using cable television?
Actually, the answer is simple. No matter what data is being transferred
along a wire, it's really just an electronic signal. It's up to the
equipment at each end of the wire to decode that signal and to decide what
to do with it. The reality is that the cable companies are ultimately
connected to the same international fiber-optic system as everyone else;
they just deliver data to your house via a different medium. It's this
different medium that lets them offer another alternative to Internet
Perhaps the most significant difference between DSL and cable Internet
access is the fact that cable is essentially a shared-bandwidth
technology. In other words, with DSL service, you're allocated a certain
fixed amount of bandwidth. This bandwidth will never decrease or increase;
you paid for that bandwidth, and it's all yours. But with a cable modem,
you aren't guaranteed exclusive access to the total available amount of
bandwidth. Because of the way cable networks are set up, there may be
times when you're able to use a full 6Mbps of bandwidth, but there may be
other times you are limited to 256Kbps or 128Kbps, or whatever happens to
Here's why. With cable
Internet service, an access point is shared by everyone within a certain
area. Although maximum throughput varies depending on the equipment used,
this access point generally provides about 10Mbps of bandwidth. If no one
else within your access point area is on the Internet, you have the full
10Mbps to yourself, even if your service is only supposed to offer, say,
384Kbps. However, if many people are online, your connection will slow
down. If this slowdown occurs regularly, the only solution is for the
cable company to install another access point. Of course, you may or may
not be able to compel the provider to add that additional access point.
That's one of the risks of using cable.
A shared access point also carries some special security risks.
Essentially, every computer that uses that access point for Internet
access is part of the same network. In effect, this network functions like
the LAN (local-area network) you probably have at work, which makes it
easy to share files and access other computers within the network. This
configuration is great in the office, where you generally want everyone to
be able to share certain resources. But it's not so great at home: Your
last year's tax returns could end up being shared with everyone in your
neighborhood. To avoid this scenario, be sure to disable file sharing on
your computer. To do so, follow these steps:
- Go to the Start button and
- Choose Control Panel.
- Double-click the Network
- Click the File And Print
- Uncheck the File Access
and Print Access checkboxes.
Cable modems and routers
Cable Internet access requires that a cable modem be installed in your
house. From an end-user's perspective, a cable modem functions the same as
a DSL router. It provides an address for your computer, and is responsible
for all communication with the Internet. As far as most users are
concerned, the only difference is whether you're plugging a phone cord or
a coaxial cable into it. From a technological point of view, however,
cable and DSL are as different as apples and oranges. Knowing the pros and
cons of each, it's up to you to decide which to pick. Either way, you're
bound to enjoy the higher access speed.
Between DSL & Cable
If you have the luxury of choosing between DSL and cable Internet access,
here are some tips to help you choose the one that's right for you.
Infrastructure and service
Think about the quality of cable and phone service in your area. Have you
dealt with these companies in the past? Were they easy to work with? If
your phone is constantly cutting out, but your cable reception is perfect,
that's a vote for cable. On the other hand, if every week your cable
picture turns to snow right in the middle of "The Simpson's" (and if the
folks at the cable TV office seem unresponsive to your plight), perhaps
Internet service won't be much better.
Is one company thriving and expanding while the others are struggling to
cut costs? This could be an indication of the company's ability to expand
its offerings in the future. These days, a technology company can go from
"standard cost-cutting measures" to Chapter 11 in a matter of weeks.
How many people live in your area, and what are they like? If your area is
filled with young professionals living in condominiums, DSL might be a
better choice because of its guaranteed bandwidth. However, if the Shady
Meadows Retirement Community surrounds your house, it's possible you'll
get great cable access. (Except that you'd be surprised at the number of
retirement-aged folks who are surfing the Internet these days.)
Some cable providers have policies about the "average bandwidth" they will
provide to their customers. In effect, this says, "When you, the customer,
are no longer getting 1Mbps of bandwidth, we, the cable provider, will
install another access point." Not every provider has such a policy (and
their policies can change, of course) but it's worth checking out. This
can take some of the guesswork out of what your bandwidth would be like
with cable. Be sure to ask your provider about this before signing up.
Some Internet providers require you to lease the router or cable modem;
others require that you purchase it. Some companies will give you the
router or modem free, if you sign up for a year of service. Each company
has different guidelines regarding their CPE (customer premises
equipment), so be sure to ask questions and make sure you understand all
of the options before you sign a contract.
The loopback test
If you're looking at DSL service, the first thing the provider will do is
run a loopback test. They'll send data along the phone lines between your
home or office and the nearest office of the DSL provider. They measure
the time it takes for the signal to get to, and return from, your
location. They also measure the attenuation, or degradation, of the
signal. These two factors give the DSL provider a good indication of what
the maximum throughput would be on your line. If you live a long way away
from the DSL office, or if the wires along which the signal travels are
old, your maximum throughput may be too low to make DSL worthwhile. When
considering a move to DSL, make sure the provider shares the results of
this test with you.
After you've decided which type of service to go with, it's time to start
the process of actually getting the service. The first step is to check
out the available plans. Both DSL and cable are "always on" connections,
so the plans normally won't be rated in hours. However, especially with
DSL, there are some significantly different plans from which to choose.
Some DSL providers will charge you for throughput. Some companies will
offer a choice of bandwidth options on a sliding scale (the more
bandwidth, the more money). Other providers offer only one plan to their
residential customers. Whether you have one or 100 plans from which to
choose, don't consider any plans offering less than 384Kbps. If you can't
get 384Kbps at a price you can afford, you're being ripped off. Another
company may be able to offer you something better. Secondly, never get a
DSL plan that places a limit on the amount of data you can transfer.
Plans that limit the amount
of data you transfer work like this: The company offers "unlimited hours"
of DSL service. Be wary, though; to the company, this may not mean
"unlimited surfing." Somewhere in the fine print, the contract may limit
the amount of data that can be transferred to your computer. For example,
you may be permitted to download a total of 100MB of data during any
single month, but the ISP may levy a surcharge once you exceed that limit.
(Remember the 100MB limit includes not only files you explicitly
downloaded, but also whatever Web pages and components you viewed, because
you have to download them to view them.) One provider permits total
throughput of 20GB, but charges $100 for each additional 35GB of
throughput. These plans are bad news, because once you start streaming
video or downloading music, you'll use up your allocated bandwidth in no
time. Then you're stuck rationing your time online, or avoiding sites that
are too bandwidth-intensive. This defeats the whole purpose of upgrading
to DSL in the first place. So, read the fine print. Your Internet
connection should have no limits on time or the amount of data you can
Signing up for cable is usually simpler. As noted earlier, whatever
bandwidth is available in your location is shared by everyone in that
area. Because of this, there's no way to guarantee, and thus no easy way
to track, how much bandwidth you're using. For residential customers,
there is usually only one service plan.
The static IP option
There's one more option to consider, and this one applies to both cable
and DSL: Do you want a static or a dynamic IP address? Static IP addresses
sometimes cost a few extra dollars per month but, in certain situations,
you may decide they're worth the cost.
An IP address is just like a
postal address for your computer, except that instead of telling other
people where to reach you by mail, it tells other computers how to reach
your computer electronically.
Your DSL router or cable
modem will reset its connection to the home office every so often and,
naturally, whenever you power down and then get back online later.
Whenever it does this, if you have a dynamic IP address, your router (or
modem) and your computer are assigned new IP addresses. But if you have a
static IP address, your router (or modem) and your computer will always
keep the same IP address. A static IP address is essential if you want to
host a Web page from your computer, or access your computer's data from
another location. If you have either of these things in mind, be sure to
ask about static IP addresses.
One last thing to note: If you are considering static IP addresses, make
sure they are "routable." Some IP addresses (those beginning with "10" or
"192.168") are accessible only from within a LAN. If you plan on hosting a
Web page and your IP address isn't routable, only other computers in your
house (or, if you're using a cable modem, other people in your immediate
area) will be able to reach your computer.
Unless your new Internet provider offers free installation, you'll have to
face the eternal question of whether to install it yourself or to pay your
provider to install it for you. We'll explain what's involved in
installing a cable modem or DSL router so you can decide for yourself.
Regardless of whether you're installing a cable modem or DSL router,
you'll need a NIC (network interface card). This card will permit
communication between your computer and the modem or router. These can be
purchased at any computer store for as little as $20. Some newer computers
have NICs built in; check to see if your computer has a NIC by looking for
something on the computer that looks like a wider-than-normal telephone
If you don't have a NIC built
into your computer, you'll have to install it yourself or have someone
install it for you. Installing a NIC is just like installing other
computer peripherals, so if you've upgraded your computer in the past, you
can probably handle installing a NIC.
Once your NIC is installed and working, hooking up your DSL router or
cable modem is quite easy. There should be three cords included with your
router or modem: a phone cord or coaxial cable, an Ethernet cable, and a
power cable. First, connect the phone cord or coaxial cable from a wall
jack into your router or modem. Second, plug one end of the Ethernet cable
into your router or cable modem, and plug the other end into the NIC in
your computer. Third, connect the power cable to the router or modem and
plug it into a wall outlet. At this point, the modem or router will
connect to the provider's home office, and you should be surfing in a
matter of minutes.
If you don't want to attempt to install your router or modem yourself,
most providers will gladly do it for you. Many will bring a NIC with them,
which you can purchase if you don't have your own. They'll install and set
up your NIC, hook up your modem or router, and test it to make sure
everything works. This all sounds great, but there are two drawbacks.
First, your provider will almost certainly charge you to do the
installation. Worse, you'll probably miss a day of work, watching endless
reruns of "Bewitched" while you wait for the installer to arrive.
Don't wait too long to upgrade to DSL or cable. Each day, Web sites add
more bandwidth-intensive content. It won't be long before surfing the Web
at less than 384Kbps will be like driving your 1974 Chevy Vega in the Indy
500: You could do it, but who'd really want to try? So, choose DSL or
cable, whichever best fits your situation. Install it yourself or have
someone do it for you. Whatever you do, upgrade. Once you've experienced
the Internet with DSL or cable, you'll never go back to a dial-up
by Adam Erickson