CABLES AND CONNECTORS

Chapter 2

OBJECTIVES Upon completion of this chapter, you should

be able to: Select & install cables for connecting to a dial-up

network Select & install cables for connecting to an

Ethernet network Identify network cables by sight or name Identify network cable speed capabilities by

name Identify network connectors by sight or name Given a scenario and networking requirements,

select and install cables for communication between computers and networking devices

Troubleshoot issues with networking media

TWISTED PAIR

2.1

USING TWISTED PAIR Pairs of copper wire wrapped in

insulation, twisted around each other Electrical pulses Inexpensive & easy to work with

Look up a 500ft roll of Cat6 cable

THE TWISTS Crosstalk

Small amount of electricity leaks & jumps to other wires

Problem if you have wires close to each other

Twisting cancels out crosstalk

TWISTED PAIR

ADVANTAGES DISADVANTAGES

Less expensive Very flexible Easy to run Newer, faster

standards designed to run on twisted pair

Thin outer covering EMI

Keep away from fluorescent lights

Distance limit Possible

eavesdropping

TYPES OF TWISTED PAIR CABLES Cat3

Old, slow (10Mbps) Cat5

100Mbps Cat5e

1000Mbps/1GbpsBetter against crosstalk/EMI

Cat61Gbps & up10Gbps not recommendedMust use shorter lengths or use Cat6a

TWISTED PAIR CONNECTORS RJ11

4 connectors, 2 pairs of wirePhone/DSL

RJ458 connectors, 4 pairs of wireEthernet

REVIEW- 5Q Category 6 cables have how many wires in

them? 8

Which connector is used for phone cables? RJ11

Which connector is used for Ethernet? RJ45

Why are twisted pair cabling wires twisted? To reduce crosstalk

When installing twisted pair cabling, what would you keep it away from? Fluorescent lights

ACTIVITY TestOut Lab 2.1.3

Connect to an Ethernet Network

Quiz on 2.1.4

COAXIAL CABLE

2.2

COAXIAL- QUICK OVERVIEW Used in very early Ethernet & now for TV

Wireless antenna connectionsCable Internet

Shielding Thicker cable BNC or F-connector RG-6 (current cable TV), RG-59 (older

cable TV), RG-58 (old Ethernet)

COAXIAL

ADVANTAGES DISADVANTAGES

Pretty resistant to EMI

Harder to physically damage

More expensive to install

Thicker than twisted pair

Less flexible & harder to install than twisted pair

High speed networking doesn’t support coax

ACTIVITY TestOut

2.2.3 Connect a Cable Modem Lab

2.2.4 Quiz

REVIEW- 4Q What kind of common connectors would

be on a coax cable? F or BNC

What kind of signal travels on a coax cable? Electricity

If you have a cable modem, what type of coax cable do you have? RG-6

Which cable protects against EMI better, RG-6 or Cat 5e? RG-6

REVIEW- 5Q What connector would be on a Cat 5 or 6 cable?

RJ45 What in the ceiling could “mess up” the electrical

signal in an UTP cable? Fluorescent lights, electrical boxes/equipment

An electrical motor near a UTP cable causes what kind of interference? EMI

Signals from one cable jump into another. What problem is this? Crosstalk

What is the solution to prevent crosstalk on UTP? Twisting of the pairs

FIBER OPTIC CABLE

2.3

FIBER OPTIC Transmits pulses of light

Laser or LED Glass or plastic core No EMI/RFI; no lightning

attraction Used for high speed & long

distanceLAN backboneConnect ISP to Internet

2 fibers cables usedTransmit & receive

FIBER OPTIC CABLE

ADVANTAGES DISADVANTAGES

Resistant to EMI No way to

eavesdrop on the signal

Fast speeds

Very expensive Used in backbone Fragile cable Difficult to attach

connector to cable

TYPES OF FIBER CABLES Multimode

LEDMany paths of light (thick)Used in LANs/Campuses

2000 meters Less $, used more

Single ModeLaser lightSingle, thin path of lightConnects backbone/NOCs

3000 meters More $, faster speed

FIBER CONNECTORS

ACTIVITY-USE LOW OR HIGH

Issue UTP Fiber Optic

Bandwidth

Distance

Immunity to EMI/RFI

Immunity to Electrical Hazards

Media/Connector cost

Installation Skill/Cost

Safety Precautions

ACTIVITY

REVIEW- 3Q Which cable is more expensive, copper

or fiber?Fiber

Which cable allows data to travel further, copper or fiber?Fiber

Why are two strands of fiber used for communication?Light can only travel in one direction at a

time. This will allow for full-duplex.

REVIEW- 3Q What signal travel on a single-mode

cable?Laser

Which cable would be used to go further distances?Single mode

Why would you use fiber between buildings rather than copper?Fiber does not attract lightning

ACTIVITY TestOut

2.3.2- Review Fiber Optic Facts2.3.3- Connect Fiber Optic Cables 1 Lab2.3.4- Connect Fiber Optic Cables 2 Lab2.3.5- Quiz

Professor Messer Videos 1.5 Cable TypesCopper Connectors (8:05)

Copper Cabling (9:28)Straight-Through, Crossover, and Rollover Cables (7:42)

Fiber Connectors (3:51)Fiber Cables (7:37)

Media Converters (3:19)Network Cabling Tools (8:13)

WIRING IMPLEMENTATION

2.4

TYPES OF UTP CABLES Straight-through

We’re going to make them Crossover

We’re going to make them

MAKING UTP CABLES TIA/EIA 568A & 568B

STRAIGHT-THROUGH CABLE 568B to 568B Connect unlike devices

Computer to Hub/Switch Switch to router port

On the PC NIC Pins 1 & 2 transmit Pins 3 & 6 receive

STRAIGHT-THROUGH CABLE Straight-through 568B to 568B

White-Orange Orange White-Green Blue White-Blue Green White-Brown Brown

CROSSOVER CABLE 568A to 568B Like Devices

Switch/hub port to switch/hub portRouter port to router portPC to router portPC to PC

CROSSOVER CABLE Crossover 568B to 568A Change Oranges & Greens

on ONE SIDE!

White-Green Green White-Orange Blue White-Blue Orange White-Brown Brown

REVIEW- 3Q What is the 568B color order?

Wor/Or, WGr/Bl, WBl/Gr, WBr/Br For speeds of 1000Mbps or more, what

Category cable should be used?Cat 6

What cable…Goes between same devices?

CrossoverGoes from PC to switch?

Straight throughGoes from serial to console port?

Rollover

REVIEW- 3Q What colors do you change for a

crossover cable?Oranges & greens

What pairs transmit?1 & 2

What pairs receive?3 & 6

WIRING DISTRIBUTION Demarc

Where Internet & phone line enter your building

Inside your building (your responsibility)

WIRING DISTRIBUTION MDF (Main Distribution

Frame) Main wiring closet near

the demarc

IDF Other wiring closets that

connect to the MDF Connect to MDF using

vertical cabling (VCC) or going up

IDFs connect to each other using horizontal cabling (HCC)

PATCH PANEL Jacks from this room go to IDF and into a

patch panel Allows you to connect wires to a punch-

down block, then use patch cables to connect to a switchGives you flexibility in moving cablesAllows for easy labeling

PUNCH DOWN BLOCK Using punch down tool

ACTIVITY Practice a Punch Down on a Patch Panel

TestOut2.4.6- Connect Patch Panel Cables 1 Lab2.4.7- Connect Patch Panel Cables 2 Lab2.4.8- Quiz

REVIEW- 5Q What is the point of where the service provider’s

wiring enters your building? Demarc

The fiber cable running down the street has been cut. Whose responsibility is it to fix it? Service provider

Near the demarc is the point where everything in your network comes together. What is this area called? MDF

There are 2 wiring closets on this floor that connect together. What are they called & what cabling connects them? IDF & Horizontal cabling

What cabling connects an IDF to the MDF? Vertical cabling

TROUBLESHOOT NETWORK MEDIA

2.5

COPPER WIRING ISSUES Interference

Unwanted signalsEMI causes (generators, transformers, high-

power lines, fluorescent lights)

ELIMINATE INTERFERENCE Use fiber instead of copper Use STP cable

CROSSTALK Signal jumps from one wire to another

within the cable & disrupts the data

NEXTMeasurement of crosstalk at one connector

end FEXT

Measurement of crosstalk on other end

PREVENTING CROSSTALK Properly connected connectors Maintain the twists

When putting on a connectorAt the punch down block

ATTENUATION Loss of signal strength over long cable

runs

Prevent itDon’t exceed max distance of cableEthernet is 100m max!Keep out of very hot areasUse a repeater if necessary (amplifies the

signal)

SHORTS & OPENS Shorts

Signal hops to another exposed wireSignal grounds out (nail through wire)

OpensBreak in wire

SPLIT PAIR Wires may go to correct pins but twists

with wrong cable to cancel signal out (prevent crosstalk)

TROUBLESHOOTING FIBER Connector issues

Use right connector so fiber lines upDirty connector or jack prevents light/signal

Cable issuesBending cable too tight breaks the coreMismatch of single/multimode cable= 99%

loss

Signal LossCable length, connectors, splices

TROUBLESHOOTING TOOLS Loopback plug

Cable Tester

Review TestOut

2.5.5

REVIEW- 3Q The signal on your 400ft UTP run gets weak

at the destination, causing the signal to be unreadable. What is the problem? Attenuation

Unwanted signals are added to your Ethernet cable running over fluorescent lights. What’s the problem? EMI

The Ethernet cable you made is having problems. Signals are jumping from one wire in the cable to another in the cable. What’s the problem? Crosstalk

ACTIVITY Watch Professor Messer Videos

4.4 – Copper Cable IssuesTroubleshooting Copper Cables (6:19)Troubleshooting Signal Loss (6:15)Troubleshooting Network Cabling (4:27)

4.5 – Fiber IssuesTroubleshooting Fiber Issues (5:11)

REVIEW & STUDY Complete the study guide handout

Take all quizzes on TestOut

Jeopardy review

CABLES AND CONNECTORS

Chapter 2