Networking Topologies, Connectors, and Wiring Standards

Question 1

Why would a network administrator use plenum-rated cable during an installation? (Choose two.)

Low combustion temperature

High combustion temperature

Reduces toxic gas released during a fire

Is not susceptible to any interference

Answer 1

High combustion temperature

Reduces toxic gas released during a fire

Plenum-rated means that the cable’s coating doesn’t begin burning until a much higher temperature of heat, doesn’t release as many toxic fumes as PVC when it does burn, and is rated for use in air plenums that carry breathable air, usually as nonenclosed fresh-air return pathways that share space with cabling

Question 2

Which of the following Ethernet unshielded twisted-pair cabling types is/are commonly used?

10BaseT

100BaseTX

1000BaseTX

All of the above

Answer 2

All of the above

UTP is commonly used in twisted-pair Ethernet like 10BaseT, 100BaseTX, 1000BaseTX, and so on

Question 3

In which of the following categories is UTP cable not rated?

Category 3

Category 5e

Category 9

Answer 3

Category 9

Unshielded twisted-pair has standards from Category 2 through 8 for use on Ethernet networks. There is no Category 9 defined

Question 4

What type of connector does UTP cable typically use?

BNC

ST

RJ-45

Answer 4

RJ-45

UTP usually connects with RJ-45. You use a crimper to attach an RJ connector to a cable

Question 5

Which of the following provides the longest cable run distance?

Single-mode fiber

Multimode fiber

Category 3 UTP

Answer 5

Single-mode fiber

Single-mode fiber allows for the maximum cable run distances

Question 6

You need to crimp on a connector using an RJ-45 connector. Which pin-out configuration would you use to connect a host into a switch?

UTP

Straight-through

Crossover

Answer 6

Straight-through

You would use a straight-through cable to connect a host to a switch, and the typical pin-out is called T568A

Question 7

Why is fiber-optic cable immune to electromagnetic interference (EMI) and radio frequency interference (RFI)?

Because it transmits analog signals using electricity

Because it transmits analog signals using light impulses

Because it transmits digital signals using light impulses

Answer 7

Because it transmits digital signals using light impulses

Fiber-optic cable transmits digital signals using light impulses rather than electricity; therefore, it is immune to EMI and RFI

Question 8

What type of cable transmits lights from end to end?

Coax

Fiber-optic

UTP

Answer 8

Fiber-optic

Remember that fiber-optic cable transmits a digital signal using light impulses. Light is carried on either a glass or a plastic core

Question 9

What is the main difference between single-mode fiber (SMF) and multimode fiber (MMF)?

Electrical signals

Number of light rays

Number of digital signals

Answer 9

Number of light rays

The difference between single-mode fibers and multimode fibers is in the number of light rays (and thus the number of signals) they can carry. Generally speaking, multimode fiber is used for shorter-distance applications and single-mode fiber for longer distances

Question 10

What type of cable should be used if you need to make a cable run longer than 100 meters?

Category 5e

Category 6

Fiber-optic

Answer 10

Fiber-optic

Standards limit UTP to a mere 100 meters. Different fiber-optic types have different maximum lengths, but fiber-optic is the only cable type that can extend well beyond 100 meters

Question 11

Which of the following are fiber-optic connectors? (Select three.)

BNC

ST

RJ-11

SC

LC

Answer 11

ST

SC

LC

There are many different types of fiber-optic connectors. SC, ST, LC, and MT-RJ are some of the more typical connectors in use today

Question 12

You need to connect two devices on a network and they need to send voice traffic. Which of the following cables will you use?

Cat 3

Cat 5

Cat 8

Answer 12

Cat 5

To connect two devices for voice on a vertical connect, the minimum cable you can use is Category 5

Question 13

How many hosts on a half-duplex segment can talk at one time?

Zero

One

Two

Answer 13

One

In half-duplex communication, a device can either send communication or receive communication, but it cannot do both at the same time

Question 14

On which type of cable does EMI have the least effect?

Coax

Fiber-optic

UTP

Answer 14

Fiber-optic

Fiber-optic cable transmits only light (not electricity like UTP), so EMI has zero effect on it

Question 15

How many devices can be connected to a full-duplex segment?

Zero

One

Two

Answer 15

Two

Full-duplex communication requires a point-to-point configuration because the collision-avoidance circuit is disabled

Question 16

How many wires are used in a 100BaseTX UTP transmission?

Two

Four

Six

Answer 16

Four

100BaseTX utilizes only pins 1, 2, 3, and 6

Question 17

A crossover cable is used to connect all of the following except ______________.

Host to host

Hub to switch

Host to switch

Answer 17

Host to switch

All devices that are pinned the same for transmit and receive require a crossover cable to communicate directly

Question 18

How is a T1 crossover cable wired?

Pins 1, 2, 4, and 5 are connected to 4, 5, 1, and 2.

Pins 2, 3, 4, and 5 are connected to 4, 5, 1, and 2.

Pins 1, 2, 4, and 5 are connected to 3, 4, 5, and 6.

Answer 18

Pins 1, 2, 4, and 5 are connected to 4, 5, 1, and 2.

A T1 cable uses pairs 1 and 2, so connecting two T1 CSU/DSU devices back-to-back requires a crossover cable that swaps these pairs. Specifically, pins 1, 2, 4, and 5 are connected to 4, 5, 1, and 2, respectively

Question 19

The purpose of the demarcation point is to separate the customer from whom?

Headquarters

The data center

The service provider

Answer 19

The service provider

The demarcation point, or demarc, is the point at which the operational control or ownership changes from your company to a service provider. This is often at the MDF in relation to telephone connections and the CSU/DSU in regard to WAN connections

Question 20

You need to make a T568B cable for a Fast Ethernet link. How many pairs will you use?

One

Two

Three

Answer 20

Two

Fast Ethernet is 100BaseTX and this type of cable uses two pairs of wires