ITN CCNA 1 v6.0 Chapter 4 Exam

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 RFI Explanation: EMI and RFI signals can distort and corrupt data signals that are carried by copper media. These distortions usually come from radio waves and electromagnetic devices such as motors and florescent lights. Crosstalk is a disturbance that is caused by adjacent wires bundled too close together with the magnetic field of one wire affecting another. Signal attenuation is caused when an electrical signal begins to deteriorate over the length of a copper cable.

Which statement describes an extended star topology? - End devices connect to a central intermediate device, which in turn connects to other central intermediate devices. - End devices are connected together by a bus and each bus connects to a central intermediate device. - Each end system is connected to its respective neighbor via an intermediate device. - All end and intermediate devices are connected in a chain to each other.

End devices connect to a central intermediate device, which in turn connects to other central intermediate devices. Explanation: In an extended star topology, central intermediate devices interconnect other star topologies.

What are two services performed by the data link layer of the OSI model? (Choose two.)

It accepts Layer 3 packets and encapsulates them into frames. It provides media access control and performs error detection. Explanation: The data link layer is responsible for the exchange of frames between nodes over a physical network media. Specifically the data link layer performs two basic services: It accepts Layer 3 packets and encapsulates them into frames. It provides media access control and performs error detection. Path determination is a service provided at Layer 3. A Layer 2 switch builds a MAC address table as part of its operation, but path determination is not the service that is provided by the data link layer.

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

It is able to carry signals much farther than copper cabling. Explanation: Copper cabling is usually cheaper and easier to install than fiber optic cabling. However, fiber cables generally have a much greater signaling range than copper.

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

LLC

What is true concerning physical and logical topologies? The logical topology is always the same as the physical topology. Physical topologies are concerned with how a network transfers frames. Physical topologies display the IP addressing scheme of each network. Logical topologies refer to how a network transfers data between devices.

Logical topologies refer to how a network transfers data between devices. Explanation: Physical topologies show the physical interconnection of devices. Logical topologies show the way the network will transfer data between connected nodes.

Which type of connector does a network interface card use?

RJ-45

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. Explanation: When data travels on the media, it is converted into a stream of 1s and 0s. The framing process inserts into the frame start and stop indicator flags so that the destination can detect the beginning and end of the frame.

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

They allow for full-duplex connectivity. Explanation: Light can only travel in one direction down a single strand of fiber. In order to allow for full-duplex communication two strands of fiber must be connected between each device.

Fill in the blank: 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

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

data link Explanation: Encapsulation is a function of the data link layer. Different media types require different data link layer encapsulation.

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

error detection Explanation: The trailer in a data-link frame contains error detection information that is pertinent to the frame included in the FCS field. The header contains control information, such as the addressing, while the area that is indicated by the word "data" includes the data, transport layer PDU, and the IP header.

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

full duplex

Fill in the blank: A physical topology that is a variation or combination of a point-to-point, hub and spoke, or mesh topology is commonly known as a ___topology.

hybrid

What are two examples of hybrid topologies? (Choose two.) partial mesh extended star hub and spoke point-to-point full mesh

partial mesh extended star Explanation: A hybrid topology is one that is a variation or a combination of other topologies. Both partial mesh and the extended star are examples of hybrid topologies.

A network administrator is designing the layout of a new wireless network. Which three areas of concern should be accounted for when building a wireless network? (Choose three.)

security interference coverage area Explanation: The three areas of concern for wireless networks focus on the size of the coverage area, any nearby interference, and providing network security. Extensive cabling is not a concern for wireless networks, as a wireless network will require minimal cabling for providing wireless access to hosts. Mobility options are not a component of the areas of concern for wireless networks.

What is the definition of bandwidth?

the amount of data that can flow from one place to another in a given amount of time Explanation: Bandwidth is the measure of the capacity of a network medium to carry data. It is the amount of data that can move between two points on the network over a specific period of time, typically one second.

Which characteristic describes crosstalk?

the distortion of the transmitted messages from signals carried in adjacent wires Explanation: EMI and RFI can distort network signals because of interference from fluorescent lights or electric motors. Attenuation results in deterioration of the network signal as it travels along copper cabling. Wireless devices can experience loss of signals because of excessive distances from a access point, but this is not crosstalk. Crosstalk is the disturbance caused by the electric or magnetic fields of the signal carried on an adjacent wire within the same cable.

What is indicated by the term throughput?

the measure of the bits transferred across the media over a given period of time Explanation: Throughput is the measure of the transfer of bits across the media over a given period of time. Throughput is affected by a number of factors such as, EMI and latency, so it rarely matches the specified bandwidth for a network medium. The throughput measurement includes user data bits and other data bits, such as overhead, acknowledging, and encapsulation. The measure of the usable data transferred across the media is called goodput.

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

to distinguish data bits from control bits to identify where the frame starts and ends Explanation: An encoding technique converts a stream of data bits in a predefined code that can be recognized by both the transmitter and the receiver. Using predefined patterns helps to differentiate data bits from control bits and provide better media error detection.

What is a role of the Logical Link Control sublayer?

to mark frames to identify the network layer protocol being carried Explanation: There are two data link sublayers, MAC and LLC. The LLC sublayer is responsible for communicating with the network layer and for tagging frames to identify what Layer 3 protocol is encapsulated.

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 Explanation: The CRC value in the FCS field of the received frame is compared to the computed CRC value of that frame, in order to verify the integrity of the frame. If the two values do not match, then the frame is discarded.

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

twisting the wires together into pairs Explanation: To help prevent the effects of crosstalk, UTP cable wires are twisted together into pairs. Twisting the wires together causes the magnetic fields of each wire to cancel each other out.