CCNA Chapter 4 Practice Questions

Which characteristic describes crosstalk?

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

The throughput of a FastEthernet network is 80 Mb/s. The traffic overhead for established sessions, acknowledgments, and encapsulation is 15 Mb/s for the same time period. What is the goodput for this network?

65 Mb/s

A network administrator is required to upgrade wireless access to end users in a building. To provide data rates up to 1.3 Gb/s and still be backward compatible with older devices, which wireless standard should be implemented?

802.11 ac

What are two services performed by the data link layer of the OSI model? (choose two) -It encrypts data packets -it determines the path to forward packets -it accepts layer 3 packets and encapsulates them into frames -it provides media access control and performs error detection -it monitors the layer 2 communication by building a MAC address table.

It accepts Layer 3 packets and encapsulates them into frames It provides medial access control and performs error detection.

What is one advantage of using fiber optic cabling rather than copper cabling?

It is able to carry signals much farther than copper cabling.

As data travels on the media in a stream of 1s and 0s how does a receiving node identify the beginning and end of a frame?

The transmitting node inserts start and stop bits into the frame.

Refer to the exhibit. What is wrong with the displayed termination

The untwisted length of each wire is too long

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

They allow for full-duplex connectivity

What are two reasons for physical layer protocols to use frame encoding techniques? (Choose two.)

To identify where the frame starts and ends To distinguish data bits from control bits.

What is the function of the CRC value that is found in the FCS field of a frame?

To verify the integrity of the received frame.

Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media?

data link

Which method of data transfer allows information to be sent and received at the same time?

full duplex

Match the steps to the physical layer operations that occur when data is sent from one node and received at another node What is step two?

The physical layer creates the signals that represent the bits in each frame.

A network administrator is designing the layout of new wireless network. Which 3 areas of concern should be accounted for when building a wireless network? ( Choose 3) -mobility options -security -interference -coverage area -extensive cabling -packet collision

-security -interference -coverage area

What are two reasons for physical layer protocols to use frame encoding techniques? (Choose two) -To reduce the number of collisions on the media. -to distinguish data bits from control bits -to provide better media error correction -to identify where the frame starts and ends -to increase the media throughput

-to distinguish data bits from control bits -to identify where the frame starts and ends

Refer to the exhibit. The PC is connected to the console port of the switch. All the other connections are made through FastEthernet links. Which types of UTP cables can be used to connect the devices? PC---SWITCH---ROUTER1---ROUTER2

1-rollover, 2-straight-through, 3-crossover

10,000,000,000 b/s can also be written as...

10 Gb/s

A network administrator notices that some newly installed Ethernet cabling is carrying corrupt and distorted data signals. The new cabling was installed in the ceiling close to fluorescent lights and electrical equipment. Which two factors may interfere with the copper cabling and result in signal distortion and data corruption? (Choose two.) -EMI -crosstalk -RFI -signal attenuation -extended length of cabling

EMI RFI

Which statement describes an extended star topology?

End devices connect to a central intermediate device, which in turn connects to other central intermediate devices

What is one main characteristic of the data link layer?

It shields the upper layer protocol from being aware of the physical medium to be used in the communication

What is true concerning physical and logical topologies?

Logical topologies refer to how a network transfers data between devices

Refer to the exhibit. Which statement describes the media access control methods that are used by the networks in the exhibit? PC(hardline)SWITCH-network1(hardline)router(lightning bolt)-network2-router2 w/antenna(wireless connection)laptop

Network 1 uses CSMA/CD and Network 3 uses CSMA/CA

Which type of connector does a network interface card use?

RJ-45

Which statement is correct about multimode fiber?

SC-SC path cords are used with multimode fiber cables

Which statement describes signaling at the physical layer?

Sending the signals asynchronously means that they are transmitted without a clock signal.

Multimode fiber or single mode fiber? Generally used for campus backbone

Single-mode fiber -Generally used for campus backbone

The term _____________________ indicates the capacity of a medium to carry data and it is typically measured in kilobits per second (kb/s) or megabits per second (Mb/s)

bandwidth

multimode fiber or single mode fiber? Several paths of light into the fiber

multimode Fiber -Several paths of light into the fiber

Multimode fiber or single mode fiber? Generally used with LANs

multimode fiber -Generally used with LANs

multimode fiber or single mode fiber? LED as light source

multimode fiber -LED as a light source

What is indicated by the term throughput?

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

What is the purpose of the FCS field in a frame?

to determine if errors occurred in the transmission and reception

What technique is used with UTP cable to help protect against signal interference from crosstalk?

twisting the wires together into pairs.

How is the magnetic field cancellation effect enhanced in UTP cables?

By increasing and varying the number of twists in each wire pair

What acronym is used to reference the data link sublayer that identifies the network layer protocol encapsulated in the frame?

LLC

What is contained in the trailer of a data-link frame?

error detection

What are two characteristics of 802.11 wireless networks? (Choose two.) Collisions can exist in the networks They are collision-free networks. They use CSMA/CD technology Stations can transmit at any time. They use CSMA/CA technology

Collisions can exist in the networks They see CSMA/CA technology

Multimode fiber or single mode fiber? Laser as light source

Single-mode fiber -Laser as light source

Multimode fiber or single mode fiber? Only one ray of light into the fiber

Single-mode fiber -Only one ray of light into the fiber

Match the steps to the physical layer operations that occur when data is sent from one node and received at another node What is step one?

Step 1: The physical layer encodes the frames.

Match the steps to the physical layer operations that occur when data is sent from one node and received at another node What is step five?

The physical layer restores the individual signals to their bit representations

Match the steps to the physical layer operations that occur when data is sent from one node and received at another node What is step four?

The physical layer retrieves the individual signals from the media.

Match the steps to the physical layer operations that occur when data is sent from one node and received at another node What is step three?

The signals are sent on the media one at a time.