INTERNETWORKING I
CHAPTER 9 STUDY GUIDE
What is the first thing (safety-wise) you should do when working in ceilings, walls, or attics?
Turn off all power.
What are some of the precautions you should take when working with electrical devices?
Never work on a
device when it’s plugged in
Test outlets with a
multimeter
Locate all electrical
condiuts and power wires before installing cable
Property ground all
equipment
Never cut or nick a
live 120 AC line
Don’t touch live
wires!
What are some of the general safety precautions you should take when installing cable?
Wear safety glasses
Measure carefully
(measure twice, cut once)
Know where electric
wires are in the wall where you will be drilling/cutting
Keep dust down (it
can start a fire)
Make sure you have
your ladder placed correctly
Don’t wear baggy
clothes; wear long sleeves and pants to protect your arms and legs
Know where the fire
extinguishers are located
If working in a
dropped ceiling, survey the area first. Know what’s already in the ceiling.
Consult with the
building engineer/maintenance personnel for special hazards (asbestos, lead,
PCB’s, etc.)
Pick up your tools so
no one (including you!) stumbles over them
What is the connector you must use for CAT 5 cable?
RJ-45
What are the steps you go through to surface mount a telecommunication box?
1.
Select the RJ-45
jack location
2.
Run the wire to the
location, either inside or outside the wall
3.
Mount the box with
adhesive or screws
4.
Feed the wire into
the top or rear of the box
5.
Punch the wire down
into the RJ-45 jack
6.
Insert the RJ-45
jack into the box
7.
Attach the
faceplate to the box
8.
Label the box
What are some of the factors you should take into consideration when flush mounting a telecommunication box?
What type of material
is the wall made from?
Do you want to mount
boxes on wide wood baseboards?
Decide if you’re
going to use a box or a low-voltage mounting bracket
Why shouldn’t you try to flush mount a box within 5 cm. of the bottom of a wall?
Because you’ll run
into the bottom plate of the wall and you won’t be able to get the box flush.
What is the term we use to indicate the process of matching wires of a cable to the proper terminals on the telecommunication jack?
sequencing
Why is this important?
If the wires aren’t in the right sequence, you’re circuits may not work. If your circuits aren’t right, your network won’t perform properly.
What wires are used to create the two circuits in CAT 5 cable when wiring an RJ-45 or patch panel?
1,3 / 3,1 2,6 / 6,2
What is the tool called that is used to insert the cable wires into a patch panel? How is it used?
punch down tool /
punch tool
Name at least 6 do’s and dont’s of stringing cable.
DO |
DON’T |
use cable ties |
untwist more than
1.2 cm or cable for connections |
leave slack |
Minimize bend radii
(<90 degrees) |
leave service coils |
No kinks |
use support bars |
stretch cable to
“make it fit” |
use cable
management panels |
use staple guns to
attach cable |
use velcro ties |
string network
cable in the same raceway as electrical wires |
What is a cut sheet?
A rough diagram that
shows the locations of cable runs in a building
Where should labels be attached in a LAN?
·
on both ends of
the cable
·
on the
faceplates of telecommunication boxes
·
on workstation
patch cords
· on cable connections at patch panels
Name at least 4 do’s and don’ts of stringing cable from multiple spools.
DO |
DON’T |
assign a letter to
each box for identification purposes |
uncoil cable from
boxes (leave in the box) |
tie cables together
with electrical tape |
cut cables unless
they have a label on them |
bind cable ends
together with a pull string |
|
allow enough slack
to reach to the floor and extend another 50-90 cm. (service coil) |
|
cut wire with wire
cutters to get a clean cut (better signal) |
|
Name at least three ways to wall-mount UTP CAT 5. Explain what each one is.
tie wraps – a wrap
that allows you to tie the cables together and mount on a wall
decorative raceway –
wall-mounted channel with a removable cover that presents a finished apearance
gutter – same as
decorative raceway but unfinished. Usually used where it won’t be seen (attics,
dropped ceilings)
When must you use fire-rated cable?
when cable is run
where air is circulated.
What is a telepole?
A telescoping pole
with a hook at one end to hold the cable.
What is fish tape?
String or tape you
use to “fish” (pull) cable through a ceiling or wall.
What is the definition of a wiring closet? Name some of the items you might find in one.
the central junction
point for the wiring and wiring equipment used to connect devices in a LAN.
patch panels, hubs,
routers, switches, bridges
What is the difference between an IDF and a MDF?
The MDF is the main
wiring closet in the building. It is where all the other wiring closets come
together. It is usually positioned as close to the POP as possible.
The IDF is an
intermediate wiring closet (one on another floor or another catchment area on
the same floor if it’s a really big building). IDF’s are dependent on the MDF.
Together, MDF and
IDFs make an extended star physical topology.
How many pins are on a patch panel (where you would wire in one cable)?
8
Is the color-coding on punch down blocks important? Why or why not?
Yes. If you don’t get
the right wires in the right pin location, your circuits might not work. If
your circuits don’t work, your LAN won’t work.
Name the 8 steps in testing a network:
1. Divide the network
into smaller logical units
2. Test each unit,
one section at a time
3. Make a list of any
problems you find
4. Use the list to
try to find any malfunctioning network element(s)
5. Replace any bad
elements, one at a time
6. Test with each new
element. Keep testing until you find the problem.
7. Repair the bad
element.
8. Replace the bad
element if you can’t repair it.
Why is it necessary to do a baseline test? What is it used for?
It gives you a clear
picture of what the network should look like when it’s operating properly. You
can use this as a baseline to compare your network on an on-going basis. It can
help you trouble shoot problems in the future.
What is a cable tester used for? What is another name for a cable tester? Name at least 5 things it can test for.
It is a hand-held
device that can certify that cable meets the required IEEE and TIA/EIA
standards.
It is sometimes
called a time domain reflectometer (TDR)
·
to determine
cable distances (runs)
·
locate bad
connections
·
provide wire
maps
·
measure signal
attenuation
·
measure near-end
crosstalk (NEXT)
·
detect crossed
pairs
·
perform noise
level tests
·
trace cable
behind walls
How do cable testers work to find a shorted cable?
they send an
electrical impulse through the cable and then time the signal’s reflection from
the end back to the tester.
What is a crossed pair?
When wires that make
a circuit in CAT 5 cable are crossed in their pins (either in an RJ-45 jack or
patch panel) (e.g., instead of 1-3, it’s wired 1-2)
What is a split pair?
When wires that make a circuit in CAT 5 cable are split between the pins (e.g., instead of 1-3, it’s wired 3-3).
Name at least 6 things that can add noise to a copper cable.
fluorescent lights
heaters
radios
air cleaners
televisions
computers
motion sensors
radar
motors
switches
welders
auto ignitions
electronic devices of
all kinds