In recent years, those words have become something of an unspoken mantra
among school technology leaders. With the increasing importance of the Internet
in schools, a local-area network (LAN) with Internet access has become the
key to unlocking the power of computers to help kids learn. Once computers
in classrooms are connected to each other and to the Internet, students
and teachers can communicate and share knowledge electronically within a
school, across a school district, and with the outside world.
Schools have made great strides in building LANs and connecting them
to the Internet since the early part of this decade, but much work still
remains to be done. Information extrapolated from a recent survey by the
market research firm Quality Education Data (QED) suggests that about one-third
of U.S. schools have installed a LAN with Internet access. But with the
momentum provided by the federal e-rate program and the annual NetDay volunteer
events, it's clear that the day is fast approaching when most schools will
be wired.
If your school so far has been left out of the networking loop, now is
the time to roll up your sleeves and pull some wire. Drawing on our collective
experience as school technology coordinators and trainers, we're going to
provide you with a step-by-step networking road map to guide you through
the process of wiring your school.
As you start thinking about your network, ask yourself: How much of this
project can I accomplish without hiring a contractor? The task of building
a school LAN can be either fairly easy or quite complicated, depending on
the structure of your building. An older building that lacks suspended ceilings
and boasts 13-inch thick walls -- and that might even have asbestos hiding
in the ceilings or in some of the walls -- will almost certainly require
you to turn to an experienced contractor.
On the other hand, if your building has suspended ceilings and cement
block walls that allow for easy access into classrooms, you're looking at
a job that could be well-suited -- at least in part -- to a do-it-yourself
project. If that prospect sounds scary, consider that a regional technology
hub, area service center, or other agency of your state board of education
might be able to provide your school or district with technical assistance
in the design and implementation of your network.
Another option is to incorporate a NetDay event into your networking
project, giving you an opportunity to recruit cable and network professionals
in your community to volunteer their expertise. A NetDay event could also
end up saving your school anywhere from $15,000 to $20,000 -- or more --
in labor costs. (The next national NetDay
is scheduled for Oct. 24, 1998.)
If these resources or the necessary local expertise is not available,
however, then your only option might be to hire a contractor. If you go
this route, be sure to contact more than one company and write a list of
your exact needs prior to taking price quotes. That way, you won't be comparing
apples and oranges. And as you listen to the sales talk, keep that old adage
in mind: If it sounds too good to be true, it probably is.
Start with the closet
Whether you decide to do it yourself or not, the first step in your networking
project is to go over the building blueprints -- especially the "as
builts" if they are available. Doing so will help you plan the installation
of your network and anticipate problem areas before the work begins.
With floor plans in hand, begin by deciding on a location for the wiring
closet. This is where the network cables from the classrooms connect to
the equipment that runs your LAN. The networking hardware is typically assembled
in a rack not unlike a component stereo system and usually includes a patch
panel, a hub, a router, and a CSU/DSU. (See sidebar for
definitions of these terms.) This is also where your school's Internet connection
plugs into your network. The room should be at least 5 by 8 feet, with good
ventilation, and it should be lockable for security.
The wiring closet does not have to be in close proximity to a computer
lab or even to the school office, since the computer and telecommunications
hardware placed there do not normally need to be accessed unless a problem
occurs. What is necessary is that the room be located away from a
water source, which means that a custodial closet will not work. The room
also needs to be away from electromagnetic interference, which eliminates
many custodial workshops. And the requirement for good ventilation rules
out furnace rooms as well. As you can see, finding a good location for your
wiring closet might call for some creative thinking on your part. Once again,
this is where a good set of scale drawings of the entire building will be
extremely helpful.
If your school building is large, you might be forced to use two or more
wiring closets in order to avoid excessively long cable runs to the classrooms.
In general, cable runs longer than 300 feet will slow down your network.
Similarly, if the distance between multiple wiring closets exceeds 300 feet,
you might have to use fiber-optic cable to connect them to each other, adding
considerable expense to your project. (Not only is fiber-optic cable about
10 times more expensive than regular computer network cable, it also requires
special -- and costly -- hardware at each end.)
We ran into this problem with one of our high schools, which was built
in the 1920s. Three stories tall and almost a block long, the school incorporated
a vocational center across the street. In order to wire this school for
a local-area network with Internet access, we had to put a wiring closet
on each floor, connected via a fiber-optic backbone. Then we had to run
an additional fiber-optic cable across the street to a fourth wiring closet
in the vocational center.
Obviously, not every school LAN installation is likely to be this complicated.
If your school is of moderate size, chances are you'll be able to place
a single wiring closet within reach of every classroom.
Find the right path
Your next task is to examine the building blueprints to determine exactly
where to run the cables. For example, you'll want to avoid running the cables
too close to sources of electrical interference that can hurt network performance,
such as fluorescent lights and transformers. (This is not a concern with
fiber-optic cable, which is immune to electrical interference.)
Similarly, if a cable is to be pulled above a suspended ceiling, be sure
to check whether this space is part of the school's heating, ventilation,
and air conditioning (HVAC) system. If it's a plenum ceiling that is used
for an HVAC air return, you'll need to use plenum-rated cable with a special
covering that burns more slowly and gives off less-toxic fumes in case of
fire. (Naturally, this doubles the cost of the cable.) You should also note
the location of fire walls, as these will require special treatment if you
plan to drill through them for cable runs.
Once you've laid out the exact cable path from the wiring closet to each
classroom, you'll need to decide on the number of cable runs and data ports
needed per classroom. This is an area where a little overkill today can
save you a lot of aggravation tomorrow. In the past, single cable runs were
commonly made from the wiring closet to each classroom, where mini-hubs
were used to split the signal between data ports serving several computers.
Current thinking, however, calls for multiple "home runs" of two
or even four cables per classroom from the wiring closet.
Here's why: Compared to the cost of labor, cable is dirt cheap. It is
no more labor intensive to pull four cables per classroom than it is to
pull a single cable, and doing so gives you multiple backups in case of
a future cable failure. Now the malfunction of a single cable won't disconnect
all the computers in that classroom from the network.
There are times when a single cable run per classroom might be your only
alternative, however. An example of this situation might be a school building
dating from the early 1900s -- with thick walls, asbestos in the plaster,
and no suspended ceilings. In a situation such as this, you can either retrofit
suspended ceilings or surface-mount all the cables on the wall in protective
plastic channels called raceways. Installing new ceilings is usually prohibitively
expensive, however, and running multiple redundant cables in raceways can
get both expensive and impractical. In this case, your best bet might be
to go with one data drop per room, using the smallest raceway available
and a mini-hub in the classroom to split the connection between several
computers.
In the classroom, the cables terminate in a data box containing the data
ports where the computers plug into the network. Think of the data ports
as analogous to electrical or telephone outlets: You should be able to move
the computers to wherever they are needed simply by unplugging, moving,
and plugging in again. Resist the temptation to skimp on the number of data
ports, though -- your network needs are only likely to grow in the future.
Just think of all the homes and schools that were built with one electrical
outlet per wall; isn't this unsatisfactory now?
Of course, the number of data ports you'll want in each classroom depends
on how many computers you're planning to put in that room. When personal
computers were first introduced, schools put one or two computers in a classroom.
Then, as networking technology was developed, computers were moved to a
central lab. Now, in many schools, labs are passé and computers are
back in the classrooms once again.
Before you decide what's best for your school, consider whether the computers
are more likely to be used by students working on individual tasks (which
favors classroom placement) or for large-group instruction (which favors
the lab arrangement).
Cost is a factor, too, of course. Wealthy schools can afford to put computers
in classrooms as well as in computer labs, whereas schools with limited
funds tend to put computers only in a few classrooms. Some schools compromise
by placing computers on carts in classrooms: When a computer lab is called
for, the computers can be wheeled into a single room with a large number
of data ports.
Again, the design and construction of the school building will affect
your decision. With a multi-story building, the computer-on-a-cart option
might not work. Also, a high school or middle school building will have
different needs than an elementary school building. As with the purchase
of software or computers, the intended use should be the primary consideration
as you make your decision about classroom mini-labs versus full labs.
Having said all that, however, we feel that for most schools a good configuration
is to place four to five data ports in each classroom, and then wire one
or more rooms for full lab use with 30 to 35 data ports.
Once you've decided on the number of data drops per room, it's time to
calculate the length of each run. Either by using a scale drawing or some
sort of measure, determine the number of feet from the wiring closet to
where the cables will enter the classroom. Then, add the length of the diagonal
of the room to the total distance. It pays to be generous in your measurements
because network cable cannot be spliced. If a cable run needs 200 feet of
cable, 195 feet will not do.
Next, you'll need to measure the distances from the point where the cables
enter the classroom to where the data ports will be placed, so you can determine
how much raceway you'll need in each classroom. Raceway can be an expensive
part of the project, so it is important to be careful in measurements. But
don't try to cut costs by eliminating the raceway: Every classroom has several
children who like to pull on things, and the raceway is essential in protecting
your cable investment.
Plan for speed
Today, Ethernet is the most popular LAN technology. Ethernet allows for
transmission speeds of up to 10 Mbps (million bits per second), which is
plenty fast for today's applications. As you plan your network, however,
it is wise to allow for an eventual upgrade to Fast Ethernet, which provides
a maximum bandwidth of 100 Mbps.
For this reason, you should insist on using Category 5 cable, which is
rated for Fast Ethernet speeds. By doing so, you'll be able to upgrade your
network to Fast Ethernet at a later time, once 100 Mbps network hubs become
affordable for schools.
Most new computers can be ordered with built-in network interface cards
that are compatible with both Ethernet and Fast Ethernet standards for little
additional cost. These network cards can also be added to older computers
for less than $50 each.
Your network will never attain Fast Ethernet speeds, however, if you
don't treat your computer network cable with respect. It's no mean feat
to stuff 100 million bits of data down four pairs of twisted copper wire
in just one second, and if these cables are flattened, stapled, crimped,
or run at 90-degree angles without a sufficiently large turn radius, both
the signal strength and the transmission speed will suffer. It is not unusual
for a 100 Mbps network to drop to 10 Mbps or even slower if the cable has
been subjected to one or more of these misfortunes.
Fiber-optic cable is not immune to manhandling, either: Rough treatment
can break the glass thread, which completely interrupts the signal. This
is why -- regardless of the type of cable used -- every cable run should
be tested using professional equipment shortly after installation so that
you can rectify any problems right away.
Train, prepare, and pull
Now that you've planned your network, it's time to recruit and train
key staff and volunteers to help with the actual installation. You should
begin recruiting volunteers at least three weeks in advance of your NetDay,
before their calendars start filling up.
One training method we've used in our area of Illinois is to persuade
one or several business partners in the community to host a two-day "cabling
college" event. On the first day, participants learn the theory and
methods of cabling and networking in a classroom setting. They also get
hands-on practice in cable termination -- i.e., attaching connectors to
the ends of the cables. In some cases, participants might even be able to
earn some type of certification as cable installers from the vendors. The
second day is then spent wiring the school.
If a cabling college is not possible, the next best solution is to invite
a person with knowledge and experience in school networking to come and
train volunteers on the evening prior to your NetDay. Remember that it is
very important for all volunteers to be present at the training session:
Having half of the group trained and ready to go at 8 a.m. the next day
-- and the other half clueless about what to do -- is not only frustrating,
it's a recipe for technical mishaps.
Your final preparations for the wiring project will include punching
or drilling holes large enough for the data cables to enter each room in
the locations you've determined. You'll also need to remove the ceiling
tiles approximately every four feet down the hallway and in the rooms. And
don't forget to have the necessary materials on hand -- including plenty
of ladders, drills, and hacksaws for cutting raceway. Of course, the volunteers
will no doubt appreciate you for providing refreshments and lunch, too.
Some schools are fortunate to have people in the community who have experience
in pulling cable. These people should serve as team leaders if at all possible.
The number of volunteers you'll need will vary from 12 to 24 depending on
the size of your building and the number of team leaders that can be recruited.
Each cable-pulling team will have four to five members who will guide the
cable, help it over or around difficult spots, and leap-frog each other
as the cable moves down the hallway and into a classroom.
Teams of at least three will be needed to install raceway: one on each
end and a third person to stand back and "eyeball" the installation
to help keep the raceway aligned. One important factor to remember is that
ceilings and mortar lines are seldom straight, so using a level is not much
help. It's often aesthetically more pleasing to follow the lines of the
room than to make things perfectly vertical or horizontal.
As you start pulling cable, follow a few simple rules to keep things
organized. First, have a form ready for each team to record and calculate
the amount of cable left on a spool as they go along. Cable comes in 1000-foot
spools, and as the spool empties, you'll need to know which rooms you can
reach with the amount of cable that's left. It is often advantageous to
start with the rooms farthest from the wiring closet and work your way back
to the closest ones.
Another helpful rule is to color-code the ends of the cable going to
a room, tape them together, and label them with the room number before starting
a pull. After the pull, and before cutting the cable from the spools, color
code the ends again and label with the room number before sending them into
the wiring closet. With consistent color coding, you can tell the volunteers
that red is always the first termination, green the second, and so forth.
The installation of raceway and data boxes with data ports can be done
either before or after the cable is pulled, depending on the amount of help
available. If sufficient numbers of volunteers are working, teams can be
installing raceway and data boxes while others are pulling the cable. It
all depends on the size of the building, the number of team leaders, and
the size of the work force available.
The final steps are terminating and testing the cables. Terminations
in the classrooms will go much faster than those in the wiring closet, because
several people can be working at the same time. A wiring closet is a cramped
space, and the wiring rack is only 29 inches wide, so only a limited number
of people can be there at one time without getting in each other's way.
Two volunteers will usually operate the test equipment, while two or three
others correct any mistakes in the wiring of the terminations.
All this work is a lot to accomplish in one day, so don't be discouraged
if you find that you're going to need several local NetDays to finish the
job. Keep in mind that you're not only connecting your students to the future,
you're also strengthening your school's bonds with the community and learning
valuable skills at the same time. And once your school's local-area network
starts humming, you'll feel great knowing you helped build it with your
own hands.
James P.
Tenbusch is superintendent and technology coordinator
of the Allen Township Community Consolidated School District No. 65 and
the Otter Creek-Hyatt School District No. 56 in north-central Illinois.
He is a developer of classroom-based, computer-assisted instructional methods,
as well as a teacher technology trainer for the past 17 years. Harry Vaughan is technology coordinator
for a Regional Office of Education at the Illinois State Board of Education.
He has more than 20 years of experience as an expert in engaged learning
methods and networking.
For an expanded text version of this article, go to Capacitors: Empowering Technology
for School Improvement.
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