You just bought a state of the art 56K modem. The prospect of high
speed Web surfing causes an adrenaline rush. You activate your
browser and wait with anxious anticipation for your favorite web site
to speedily appear. But instead of jumping onto your screen, as you
expect, it merely crawls on as it did before. You immediately check
your connection speed, 28.8K. Your day is ruined.
Now the arduous and time consuming process of trouble shooting
begins. Did I do something wrong in the setup? Is my modem defective?
Does my Internet Service Provider have the right stuff at its end to
work with my computer and my modem? Are there any other reasons why
my dreams of racing around the Internet have turned into a slow walk?
Yes, your local phone connection.
Assuming that you have correctly installed a functioning modem and
your Internet Service Provider has compatible hardware and software,
( this is, of course, a very big assumption) then there is a very
strong probability that the phone connection between you and your
Internet Service Provider is the culprit.
There are three factors which affect a successful 56K connection,
wires, switches and where you live. As the conditions within any
factor fall below a certain threshold level your ability to get a 56K
connection decreases.
Local Phone Infrastructure
Your phone line is connected directly to what the phone company
refers to as a Central Office. These are usually buildings without
any windows. A city the size of Portland, Oregon will have about a
dozen Central Offices. These Central Offices are also connected to
each other via trunk lines. The cables, which contain many pairs of
wires, that emerge from each Central Office can run from a few yards
to several miles.
Cable Factors
Noise on your phone line will diminish your ability to get a 56K
connection. Worn cable, possibly chewed by squirrels (no joke, this
is very common), loose or corroded splices and RF interference from
local TV , radio, and amateur radio buffs in your neighborhood can
all cause noise. The higher the noise level the lower your chances of
getting a high speed connection. Keep in mind that your phone line is
active from the Central Office to the very end of the cable
regardless of where you happen to tap into it. This is important.
Your phone line does not terminate at your phone. It continues on
past your house until it reaches the end of the cable. This means
that noise can enter and affect your data connection anywhere from
the Central Office to the end of the cable in which your pair of
wires reside. [Figure 1]
Three Strikes And Your Out
The signal that leaves your modem is moved along its way by an
analog carrier. When this signal reaches a Central Office it is
switched to a digital carrier and then sent out of the Central Office
on to your Internet Service Provider. If anywhere along the route
(which includes trunk lines between Central Offices, microwave relay
stations or satellite links) the signal from your 56K modem to your
Internet Service Provider’s 56K modem changes from analog to
digital or digital to analog three or more times then you will never
get a 56K connection. [Figure 2]
Signal conversions always happen in odd numbers between you and your Internet Service Provider. Any more than one and you are out of luck. [Figure 3]
Where Does Your ISP Live?
Have you ever noticed that Internet Service Providers tend to
live next door to a Central Office. By being so physically close to a
Central Office they eliminate the problem of signal degradation
caused by cable length or noise. How far your connection is from the
Central Office makes a big difference. [Figure 4]
A modem on a phone line that is connected to a cable within half a mile of a Central Office will achieve significantly better speeds than a modem on a phone line connected to a cable three miles from a Central Office. In fact, if you are connected more than three point four miles from a Central Office your chances of getting a 56K connection are nil. Closer is better. [Figure 5]
What Can I Do?
Before you buy a 56K modem, research your phone connection. Do
you have poor line quality? Will your signal be switched three or
more times before it reaches your Internet Service Provider? Do you
live too far away from a Central Office? If you get too many Yes
answers to these questions then don’t spend your money on a 56K
modem and seek out alternatives.
Unfortunately, there are no software utilities available for any type
of personal computer that will will answer your phone connection
quality questions. You could, of course, call the local phone company
but your chances of getting any useful information on this issue are
slim to none.
The good news is that there is a line testing service provided by the
3Com corporation. Their web site
http://www.3com.com/56k/need4_56k/linetest.html describes the testing
process. It is fairly easy and could cost as little as the price of a
two minute long distance phone call to the 847 area code (Elgin,
Illinois).
It is likely that any alternative will be more expensive than a
simple 56K modem connection using an ordinary analog phone line. But,
you may have no choice. If you need the speed then consider the
following options:
1. Connect to the Internet via a cable modem provided by your local cable TV company,
2. Buy an ISDN modem and get your local phone company to connect you to an ISDN line,
3. Have your local phone company install a DSL line and modem in your house. DSL services are not available in all areas but are likely to appeal to a wide customer base because of its 256K speed and relatively moderate cost,
4. Buy a 56K modem anyway and move.
This article is copyrighted 1998-99
by Richard Ellmyer, MacSolutions Inc., Portland OR.