ITN Chapter 4

7 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?​ 1 - rollover, 2 - crossover, 3 - straight-through 1 - crossover, 2 - straight-through, 3 - rollover 1 - crossover, 2 - rollover, 3 - straight-through 1 - rollover, 2 - straight-through, 3 - crossover

1 - rollover, 2 - straight-through, 3 - crossover A straight-through cable is commonly used to interconnect a host to a switch and a switch to a router. A crossover cable is used to interconnect similar devices together like switch to a switch, a host to a host, or a router to a router. If a switch has the MDIX capability, a crossover could be used to connect the switch to the router; however, that option is not available. A rollover cable is used to connect to a router or switch console port.

4 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.) signal attenuation crosstalk EMI RFI​ extended length of cabling

EMI RFI​ 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.

19 Which statement describes an extended star topology? 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. 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.

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

10 What is one advantage of using fiber optic cabling rather than copper cabling? It is able to carry signals much farther than copper cabling. It is easier to terminate and install than copper cabling. It is usually cheaper than copper cabling. It is able to be installed around sharp bends.

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

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

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

21 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. The receiving node identifies the beginning of a frame by seeing a physical address. The transmitting node sends an out-of-band signal to the receiver about the beginning of the frame. The transmitting node sends a beacon to notify that a data frame is attached.

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

11 Why are two strands of fiber used for a single fiber optic connection? They allow for full-duplex connectivity. 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. 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.

12 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.) coverage area mobility options packet collision interference security extensive cabling

coverage area interference security 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.

13 Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media? data link transport physical application

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

20 What is contained in the trailer of a data-link frame? error detection physical address logical address data

error detection 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.

18 Which method of data transfer allows information to be sent and received at the same time? half duplex full duplex simplex multiplex

full duplex

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

partial mesh extended star 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.

3 What is the definition of bandwidth? the measure of usable data transferred over a given period of time the speed at which bits travel on the network the amount of data that can flow from one place to another in a given amount of time the measure of the transfer of bits across the media over a given period of time

the amount of data that can flow from one place to another in a given amount of time 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.

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

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

2 What is indicated by the term throughput? the capacity of a particular medium to carry data the measure of the bits transferred across the media over a given period of time the guaranteed data transfer rate offered by an ISP the measure of the usable data transferred across the media the time it takes for a message to get from sender to receiver

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

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

to distinguish data from control information to identify where the frame starts and ends 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.

22 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 to verify the physical address in the frame to compute the checksum header for the data field in the frame to verify the logical address in the frame

to verify the integrity of the received frame 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.