cisco module 4-7 test

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.

• They prevent crosstalk from causing interference on the connection.

• They increase the speed at which the data can travel.

• They allow for full-duplex connectivity.

Which characteristic describes crosstalk?

• The distortion of the network signal from fluorescent lighting

• The distortion of the transmitted messages from signals carried in adjacent wires

• The weakening of the network signal over long cable lengths

• The loss of wireless signal over excessive distance from the 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 the bundle of wires with metallic shielding

• Designing a cable infrastructure to avoid crosstalk interference

• Avoiding sharp bends during installation

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 slower than the bandwidth expected. Which three factors could influence the differences in throughput?

• The latency that is created by the number of network devices that the data is crossing

• The type of traffic that is crossing the network

• The sophistication of the encapsulation method applied to the data

• The amount of traffic that is currently crossing the network

• The bandwidth of the WAN connection to the Internet

What are two characteristics of fiber-optic cable?

• It is not affected by EMI or RFI.

• Each pair of cables is wrapped in metallic foil.

• It combines the technique of cancellation, shielding, and twisting to protect data.

• It typically contains 4 pairs of fiber-optic wires.

• It is more expensive than UTP cabling.

What is a primary role of the Physical layer in transmitting data on the network?

• Create the signals that represent the bits in each frame onto the media

• Provide physical addressing to the devices

• Determine the path packets take through the network

• Control data access to the media

With the use of unshielded twisted-pair copper wire in a network, what causes crosstalk within the cable pairs?

• The magnetic field around the adjacent pairs of wire

• The use of braided wire to shield the adjacent wire pairs

• The reflection of the electrical wave back from the far end of the cable

• The collision caused by two nodes trying to use the media simultaneously

Refer to the graphic. What type of cabling is shown?

• STP

• UTP

• Coax

• Fiber

In addition to the cable length, what two factors could interfere with the communication carried over UTP cables?

• Crosstalk

• Bandwidth

• Size of the network

• Signal modulation technique

• Electromagnetic interference