Modules 4 – 7: Ethernet Concepts

Question 1

What is the purpose of the OSI physical layer?

1. controlling access to media
2. transmitting bits across the local media
3. performing error detection on received frames
4. exchanging frames between nodes over physical network media

Answer 1

2. transmitting bits across the local media

Question 2

Why are two strands of fiber used for a single fiber optic connection?

1. The two strands allow the data to travel for longer distances without degrading.
2. They prevent crosstalk from causing interference on the connection.
3. They increase the speed at which the data can travel.
4. They allow for full-duplex connectivity.

Answer 2

4. They allow for full-duplex connectivity.

Question 3

Which characteristic describes crosstalk?

1. the distortion of the network signal from fluorescent lighting
2. the distortion of the transmitted messages from signals carried in adjacent wires
3. the weakening of the network signal over long cable lengths
4. the loss of wireless signal over excessive distance from the access point

Answer 3

2. the distortion of the transmitted messages from signals carried in adjacent wires

Question 4

Which procedure is used to reduce the effect of crosstalk in copper cables?

1. requiring proper grounding connections
2. twisting opposing circuit wire pairs together
3. wrapping the bundle of wires with metallic shielding
4. designing a cable infrastructure to avoid crosstalk interference
5. avoiding sharp bends during installation

Answer 4

2. twisting opposing circuit wire pairs together

Question 5

Copper Cables
?
?

Fiber Optic
?
?

Wireless
?
?

1. backbone cabling in an enterprise
2. guest access in a coffee shop
3. horizontal cabling structure
4. waiting rooms in a hospital
5. desktop PCs in an enterprise office
6. long-haul networks

Answer 5

Copper Cables

3. horizontal cabling structure
4. desktop PCs in an enterprise office

Fiber Optic

1. backbone cabling in an enterprise
2. long-haul networks

Wireless

2. guest access in a coffee shop
3. waiting rooms in a hospital

Question 6

A network administrator is measuring the transfer of bits across the company backbone for a mission critical financial application. The administrator notices that the network throughput appears lower than the bandwidth expected. Which three factors could influence the differences in throughput? (Choose three.)

1. the amount of traffic that is currently crossing the network
2. the sophistication of the encapsulation method applied to the data
3. the type of traffic that is crossing the network
4. the latency that is created by the number of network devices that the data is crossing
5. the bandwidth of the WAN connection to the Internet
6. the reliability of the gigabit Ethernet infrastructure of the backbone

Answer 6

1. the amount of traffic that is currently crossing the network
2. the type of traffic that is crossing the network
3. the latency that is created by the number of network devices that the data is crossing