ch 4 - 11

What is the purpose of the OSI physical layer?

• controlling access to media

• transmitting bits across the local media

• performing error detection on received frames

• exchanging frames between nodes over physical network media

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

• The two strands allow the data to travel for longer distances without degrading.

• The two strands prevent crosstalk from causing interference on the connection.

• The two strands increase the speed at which the data can travel.

• The two strands allow for full-duplex connectivity.

Which of the following describes crosstalk?

• the distortion of a network signal due to fluorescent lighting

• the distortion of a transmitted message due to signals carried in adjacent wires

• the weakening of a network signal over long cable lengths

• the loss of wireless signal over excessive distance from an access point

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

• requiring proper grounding connections

• twisting opposing-circuit wire pairs together

• wrapping a bundle of wires with metallic shielding

• designing a cable infrastructure to avoid crosstalk interference

Which type of UTP cable is used to connect a PC to a switch port?

• console

• rollover

• crossover

• straight-through

What is the definition of bandwidth?

• the speed of bits across media over a given period of time

• the speed at which bits travel on a network

• the amount of data that can flow in a given amount of time

• the measure of usable data transferred over a given period of time

Which statement correctly describes frame encoding?

• It uses the characteristic of one wave to modify another wave.

• It transmits data signals along with a clock signal that occurs at evenly spaced time durations.

• It generates the electrical, optical, or wireless signals that represent the binary numbers of the frame.

• It converts bits into a predefined code in order to provide a predictable pattern to help distinguish data bits from control bits.

Which of the following is a characteristic of UTP cabling?

• cancellation

• cladding

• immunity to electrical hazards

• woven copper braid or metallic foil

A wireless LAN is being deployed inside the new one-room office that is occupied by the park ranger. The office is located at the highest part of the national park. After network testing is complete, the technicians report that the wireless LAN signal is occasionally affected by some type of interference. What is a possible cause of the signal distortion?

• the microwave oven

• the large number of trees surrounding the office

• the elevated location where the wireless LAN was installed

• the number of wireless devices that are used in the wireless LAN

What is indicated by the term throughput?

• the guaranteed data transfer rate offered by an ISP

• the capacity of a particular medium to carry data

• the measure of the usable data transferred across media over a given period of time

• the measure of bits transferred across media over a given period of time