CISCO CHAPTER 4

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

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? 1. 802.11ac 2. 802.11n 3. 802.11b 4. 802.11g

1. 802.11ac IEEE 802.11ac: Operates in the 5 GHz frequency band providing data rates ranging from 450 Mb/s to 1.3 Gb/s (1300 Mb/s.) It is backward compatible with 802.11a/n devices.

What is one main characteristic of the data link layer? 1. It shields the upper layer protocol from being aware of the physical medium to be used in the communication. 2. It converts a stream of data bits into a predefined code. 3. It accepts Layer 3 packets and decides the path by which to forward a frame to a host on a remote network. 4. It generates the electrical or optical signals that represent the 1 and 0 on the media.

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

Fill in the blank. Why are two strands of fiber used for a single fiber optic connection? 1. They allow for full-duplex connectivity. 2. They prevent crosstalk from causing interference on the connection. 3. The two strands allow the data to travel for longer distances without degrading. 4. They increase the speed at which the data can travel.

1. They allow for full-duplex connectivity.

What are two reasons for physical layer protocols to use frame encoding techniques? (Choose two.) 1. to distinguish data bits from control bits 2. to increase the media throughput 3. to identify where the frame starts and ends 4. to reduce the number of collisions on the media 5. to provide better media error correction

1. to distinguish data bits from control bits 3. to identify where the frame starts and ends

Fill in the blank with a number. 10,000,000,000 b/s can also be written as _____ Gb/s.

10 Gb/s

Put in order, the steps to the physical layer operations that occur when data is sent from one node and received at another node. 1) The physical layer creates the signals that represent the bits in each frame 2) The physical layer encodes the frames 3) The physical layer retrieves the individual signals from the media 4) The signals are sent on the media one at a time. 5) The physical layer restores the individual signals to their bit representations

2) The physical layer encodes the frames 1) The physical layer creates the signals that represent the bits in each frame 4) The signals are sent on the media one at a time. 3) The physical layer retrieves the individual signals from the media 5) The physical layer restores the individual signals to their bit representations

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?​ 1. The receiving node identifies the beginning of a frame by seeing a physical address. 2. The transmitting node inserts start and stop bits into the frame. 3. The transmitting node sends an out-of-band signal to the receiver about the beginning of the frame. 4. The transmitting node sends a beacon to notify that a data frame is attached.

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

What are two characteristics of 802.11 wireless networks? (Choose two.) 1. Stations can transmit at any time. 2. They are collision-free networks. 3. They use CSMA/CA technology. 4. Collisions can exist in the networks. 5. They use CSMA/CD technology.

2. They are collision-free networks. 3. They use CSMA/CA technology.

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.) 1. crosstalk 2. signal attenuation 3. EMI 4. extended length of cabling 5. RFI​

3. EMI 5. RFI​

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.) 1. mobility options 2. extensive cabling 3. interference 4. coverage area 5. packet collision 6. security

3. interference 4. coverage area 6. security

What is one advantage of using fiber optic cabling rather than copper cabling? 1. It is usually cheaper than copper cabling. 2. It is able to be installed around sharp bends. 3. It is easier to terminate and install than copper cabling. 4. It is able to carry signals much farther than copper cabling.

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

Which statement is correct about multimode fiber? 1. Multimode fiber cables carry signals from multiple connected sending devices. 2. Multimode fiber commonly uses a laser as a light source. 3. SC-ST patch cords are used with multimode fiber cables. 4. SC-SC patch cords are used with multimode fiber cables.

4. SC-SC patch cords are used with multimode fiber cables.

How is the magnetic field cancellation effect enhanced in UTP cables? 1. by increasing the thickness of the copper wires 2. by increasing the thickness of the PVC sheath that encases all the wires 3. by decreasing the number of wires that are used to carry data 4. by increasing and varying the number of twists in each wire pair

4. by increasing and varying the number of twists in each wire pair

Which layer of the OSI model is responsible for specifying the encapsulation method used for specific types of media? 1. physical 2. application 3. transport 4. data link

4. data link

The throughput of a FastEthernet network is 80 Mb/s. The traffic overhead for establishing sessions, acknowledgments, and encapsulation is 15 Mb/s for the same time period. What is the goodput for this network? 1. 55 Mb/s 2. 15 Mb/s 3. 65 Mb/s 4. 95 Mb/s 5. 80 Mb/s

65 Mb/s Goodput = Throughput minus Traffic Overhead for established sessions, acknowledgements, and encapsulation

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

LLC (LOGICAL LINK CONTROL)

What is true concerning physical and logical topologies? 1. Physical topologies are concerned with how a network transfers frames. 2. Logical topologies determine the media access control method used. 3. Physical topologies display the IP addressing scheme of each network. 4. The logical topology is always the same as the physical topology.

Logical topologies determine the media access control method used.

Which statement describes signaling at the physical layer? 1. Sending the signals asynchronously means that they are transmitted without a clock signal.* 2. In signaling, a 1 always represents voltage and a 0 always represents the absence of voltage. 3. Wireless encoding includes sending a series of clicks to delimit the frames. 4. Signaling is a method of converting a stream of data into a predefined code.

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

What is the purpose of the FCS field in a frame? 1. to obtain the MAC address of the sending node 2. to compute the CRC header for the data field 3. to verify the logical address of the sending node 4. to determine if errors occurred in the transmission and reception

To determine if errors occurred in the transmission and reception