Describe Structured Cabling Systems

Question 1

Name three categories of systems used in a LAN

Answer 1

Voice (telephone, modem, fax), data (LAN), video (CATV, CCTV)

Question 2

Name three typical network topographies and describe each

Answer 2

Star - direct lines to a central hub from each device
Bus - all devices distributed along one cable
Ring - all devices connected in a circle, along one cable

Question 3

What typical topography is most commonly used for structured cabling?

Answer 3

Star

Question 4

What name is given to the vertical and horizontal cables that run from the equipment room to the telecommunications closet?

Answer 4

Backbone cables

Question 5

What name is given to the cables that run from the telecommunications closet to the work area?

Answer 5

Horizontal cables

Question 6

What is the purpose of the telecommunications closet?

Answer 6

A point to interconnect backbone cables and horizontal cables via a hub or patch panel

Question 7

What is the maximum length of a horizontal cable?

Answer 7

90m (295 ft)

Question 8

What is the maximum length for patch cords or jumpers?

Answer 8

10m (30 ft)

Question 9

What is the minimum number of outlets for each work area?

Answer 9

Two

Question 10

What is the difference between a code and a standard?

Answer 10

Codes - govern installation practices

Standards - exist as guidelines to installation practices

Question 11

What CEC section refers to “Electrical Communication Systems”?

Answer 11

Section 60

Question 12

Identify the most recent Canadian and American “Telecommunications Wiring Standard”

Answer 12

Canadian - CSA T529-95

American - ANSI/TIA/EIA-568-C

Question 13

Identify three types of LAN cables

Answer 13

• Twisted pair
• Coaxial
• Fibre-optic

Question 14

Why is UTP cable twisted?

Answer 14

Twisting causes the electromagnetic coupling from one wire to another to be cancelled out, thus eliminating the interfering crosstalk between pairs

Question 15

What is the difference between shielded and screened twisted-pair cables?

Answer 15

Screened - one overall shield

Shielded - shield on each pair and overall shield

Question 16

Identify three uses of coaxial cable

Answer 16

• Computer networks
• CATV
• Video systems (CCTV)

Question 17

What is the difference in transmission frequency between Category 3 and Category 5?

Answer 17

(Category 5) 100MHz - (Category 3) 16MHz = 84 MHz

Question 18

How can a cable installer visually distinguish between a Category 3 cable and a Category 5 cable?

Answer 18

Category 5 has more twists than Category 3 cable. Also check the label on the jacket

Question 19

Should standard untwisted quad cable be installed in any new installation?

Answer 19

Standard quad cable should only be used for non-communications applications such as doorbells