Modules 4-7: Ethernet Concepts Exam Answers

what is a point-to-point topology?

A point-to-point topology is where each device is connected to other device.

what is the requirement of the mesh topology?

mesh topology requires point-to-point link with every system being connected to every other system.

What is the copper media limited by?

The copper media is limited by distance and signal interference.

what factors that cause throughput from not matching the specified bandwidth of physical links?

- amount of traffic - type of traffic - latency created by the network devices the data has to cross.

EMI or RFI

Electromagnetic Interference or Radio-frequency interference

what does the OSI physical layer provide to transport the bits that make up a frame across the network media?

It provides the means to transport the bits that make up a frame across the network media. This layer accepts a complete frame from the data link layer and encode it as a signals that are transmitted to the local media.

What is media arbitration?

Media arbitration is a collection of method that ensure that user can access attached resources without the interference of other user.

What is Radio Frequency Interference (RFI)?

Radio Frequency Interference (RFI) is the interference that is caused by radio transmitters and other devices that are transmitting in the same frequency.

Which sources are the electrical pulses susceptible to interference from?

The electrical pulses are susceptible to interference from 2 sources: - electromagnetic interference (EMI) or radio frequency interference (RFI) - crosstalk

How many pair of color-coded wire that the UTP cable consist of?

There are 4 pairs of color-coded wires that have been twisted together and then encased in a flexible plastic sheath.

Latency

Time it takes for a bit to travel from its sender to its receiver.

What are two characteristics of fiber-optic cable? (Choose two.) a. It is not affected by EMI or RFI. b. Each pair of cables is wrapped in metallic foil. c. It combines the technique of cancellation, shielding, and twisting to protect data. d. It typically contains 4 pairs of fiber-optic wires. f. It is more expensive than UTP cabling is.

a. It is not affected by EMI or RFI b. It is more expensive than UTP cabling

Fill the blank: a. All the data link layer encapsulate _______________ within the data field of the frame. b. The structure of the frame and the field that are contained in the header vary according to the ________________ c. Data link layer may use different field like priority/____________ of service, ___________ connection control, ____________ link control, _____________ control, ______________ control

a. Layer 3 PDU b. protocol c. quality, link, physical, flow, congestion

True or False: a. Fiber-optic cabling supports higher bandwidth than UTP for longer distances b. Fiber is not immune to EMI or RFI c. Fiber cost less than UTP, STP d. Fiber requires more safety precautions.

a. True b. False b. False c. True

What is a primary role of the Physical layer in transmitting data on the network? a. create the signals that represent the bits in each frame on to the media b. provide physical addressing to the devices c. determine the path packets take through the network d. control data access to the media

a. create the signals that represent the bits in each frame on to the media

In addition to the cable length, what two factors could interfere with the communication carried over UTP cables? (Choose two.) a. crosstalk b. bandwidth c. size of the network d. signal modulation technique f. electromagnetic interference

a. crosstalk f. electromagnetic interference

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.) a. the amount of traffic that is currently crossing the network b. the sophistication of the encapsulation method applied to the data c. the type of traffic that is crossing the network the latency that is created by the number of network devices that the data is crossing d. the bandwidth of the WAN connection to the Internet e. the reliability of the gigabit Ethernet infrastructure of the backbone

a. the amount of traffic that is currently crossing the network b. the type of traffic that is crossing the network c. the latency that is created by the number of network devices that the data is crossing

With the use of unshielded twisted-pair copper wire in a network, what causes crosstalk within the cable pairs? a. the magnetic field around the adjacent pairs of wire b. the use of braided wire to shield the adjacent wire pairs c. the reflection of the electrical wave back from the far end of the cable d. the collision caused by two nodes trying to use the media simultaneously

a. the magnetic field around the adjacent pairs of wire

What is the function of the CRC value that is found in the FCS field of a frame? a. to verify the integrity of the received frame b. to verify the physical address in the frame c. to verify the logical address in the frame d. to compute the checksum header for the data field in the frame

a. to verify the integrity of the received frame

what is auto-MDIX?

auto-MDIX enables a switch to use a crossover or a straight-through Ethernet cable to connect to a device.

Refer to the graphic. What type of cabling is shown? a. STP b. UTP c. coax d. fiber

b. UTP

A network team is comparing physical WAN topologies for connecting remote sites to a headquarters building. Which topology provides high availability and connects some, but not all, remote sites? a. mesh b. partial mesh c. hub and spoke d. point-to-point

b. partial mesh

Which characteristic describes crosstalk? a. the distortion of the network signal from fluorescent lighting b. the distortion of the transmitted messages from signals carried in adjacent wires c. the weakening of the network signal over long cable lengths d. the loss of wireless signal over excessive distance from the access point

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

What is the purpose of the OSI physical layer? a. controlling access to media b. transmitting bits across the local media c. performing error detection on received frames d. exchanging frames between nodes over physical network media

b. transmitting bits across the local media

Which procedure is used to reduce the effect of crosstalk in copper cables? a. requiring proper grounding connections b. twisting opposing circuit wire pairs together c. wrapping the bundle of wires with metallic shielding d. designing a cable infrastructure to avoid crosstalk interference e. avoiding sharp bends during installation

b. twisting opposing circuit wire pairs together

Which two fields or features does Ethernet examine to determine if a received frame is passed to the data link layer or discarded by the NIC? (Choose two.) a. auto-MDIX b. CEF c. Frame Check Sequence d. minimum frame size e. source MAC address

c. Frame Check Sequence d. minimum frame size

Which two statements describe the services provided by the data link layer? (Choose two.) a. It defines the end-to-end delivery addressing scheme. b. It maintains the path between the source and destination devices during the data transmission. c. It manages the access of frames to the network media. d. It provides reliable delivery through link establishment and flow control. e. It ensures that application data will be transmitted according to the prioritization. f. It packages various Layer 3 PDUs into a frame format that is compatible with the network interface.

c. It manages the access of frames to the network media. f. It packages various Layer 3 PDUs into a frame format that is compatible with the network interface.

Which statement describes a characteristic of the frame header fields of the data link layer? a. They all include the flow control and logical connection fields. b. Ethernet frame header fields contain Layer 3 source and destination addresses. c. They vary depending on protocols. d. They include information on user applications.

c. They vary depending on protocols.

Which two devices commonly affect wireless networks? (Choose two.) a. Blu-ray players b. home theaters c. cordless phones d. microwaves e. incandescent light bulbs f. external hard drives

c. cordless phones d. microwaves

Which media communication type does not require media arbitration in the data link layer? a. deterministic b. half-duplex c. full-duplex d. controlled access

c. full-duplex

what is crosstalk?

crosstalk is a type of noise, or interference that occurs when signal transmission on one wire interferes with another wire.

Why are two strands of fiber used for a single fiber optic connection? a. The two strands allow the data to travel for longer distances without degrading. b. They prevent crosstalk from causing interference on the connection. c. They increase the speed at which the data can travel. d. They allow for full-duplex connectivity.

d. They allow for full-duplex connectivity.

What is contained in the trailer of a data-link frame? a. logical address b. physical address c. data d. error detection

d. error detection

Refer to the graphic. What type of cabling is shown? a. STP b. UTP c. coax d. fiber

d. fiber

How is data transmitted on copper cables?

data is transmitted on copper cables as electrical pulses.

what is the characteristic of partial mesh topology?

partial mesh topology provides: - high availability by interconnecting remote site but do not require a connection between all the remote sites.

What is a PDU called at the Link layer?

power distribution unit is a device for controlling electrical power in a data center.

throughput

the amount of material or items passing through a system or process.

how many sublayer is the data link layer divided into?

the data link is divided into 2 sub layers, namely Logical Link Control (LLC) and Media Access Control (MAC).

UTP cable

twisted copper wires surrounded by a plastic jacket