Chapter 4 Quiz CCNA - CIS 070

Which two engineering organizations define open standards and protocols that apply to the data link layer? (Choose two.)

International Organization for Standardization (ISO) International Telecommunication Union (ITU) Refer to curriculum topic: 4.3.3 The IANA is responsible for overseeing and managing IP address allocation, domain name management, and protocol identifiers. The EIA is an international standards and trade alliance for electronics organizations, and is best known for its standards related to electrical wiring, connectors, and the 19-inch racks used to mount networking equipment. The ISOC promotes the open development, evolution, and use of the Internet throughout the world.

What is the correct color order of wire when terminating a cable by the T568B standard? Match the correct RJ-45 pin order to the wire color. (Not all options are used.)

Pin 1 - white/orange Pin 2 - orange Pin 3 - white/green Pin 4 - blue Pin 5 - white/blue Pin 6 - green Pin 7 - white/brown Pin 8 - brown Refer to curriculum topic: 4.2.2 Place the options in the following order for an Ethernet T568B cable: white/orange, orange, white/green, blue, white/blue, green, white/brown, brown. The yellow and red colored cables are not used.

What is a characteristic of a WAN hub-and-spoke topology?

The branch sites are connected to a central site through point-to-point links.​ Refer to curriculum topic: 4.4.2 A hub-and-spoke topology is a WAN version of the star topology in which a central site interconnects branch sites using point-to-point links. A mesh topology requires that every end system be interconnected to every other system using point-to-point links. A partial mesh is a variation of this topology, where some but not all end devices are interconnected. There is no topology where all the sites have to have hub devices that are connected to a router.

Which two statements are true of the deterministic access method? (Choose two.)

The throughput is predictable. Devices take turns transmitting. Refer to curriculum topic: 4.4.3 In a controlled access method, network devices take turns, in sequence, to access the media. If an end device does not have any data to transmit, then the opportunity passes to the next end device. If one end device places a frame on the media, no other device can do so until the frame has arrived at the destination and has been processed by the destination. It is non-collision, well-ordered method and provides predictable throughput. However, it can be inefficient, because a device has to wait for its turn before it can use the medium.

Which statement describes a characteristic of the frame header fields of the data link layer?

They vary depending on protocols. Refer to curriculum topic: 4.4.4 All data link layer protocols encapsulate the Layer 3 PDU within the data field of the frame. However, the structure of the frame and the fields that are contained in the header vary according to the protocol. Different data link layer protocols may use different fields, like priority/quality of service, logical connection control, physical link control, flow control, and congestion control.

Match each type of frame field to its function. (Not all options are used.)

addressing - This field helps to direct the frame toward its destination. error detection - This field checks if the frame has been damaged during the transfer. type - This field is used by the LLC to identify the Layer 3 protocol. frame start - This field identifies the beginning of a frame.

An administrator measured the transfer of usable data across a 100 Mb/s physical channel over a given period of time and obtained 60 Mb/s. Which kind of measurement did the administrator obtain?

goodput Refer to curriculum topic: 4.1.3 Goodput is the measure of usable data transferred over a given period of time. It is the throughput minus traffic overhead for establishing sessions, acknowledgments, and encapsulation. Throughput is the measure of the transfer of bits across the media over a given period of time. Digital bandwidth measures the amount of information that can flow from one place to another in a given amount of time. Latency is a measure of time delay that is experienced in a network.

Which two factors influence the method that is used for media access control? (Choose two.)

how the connection between nodes appears to the data link layer how nodes share the media Refer to curriculum topic: 4.4.1 The media access control method used depends on the topology (how the connection between the nodes appears to the data link layer), and how the nodes share the media. The type of data generated by end devices applications, the way signals are encoded by the NICs on end devices, and even the way the IP protocol forwards the packet through the network have no influence on the choice of the method used for media access control.

In fiber optic media, the signals are represented as patterns of ___

light Refer to curriculum topic: 4.1.2 In fiber optic media, the physical layer produces the representation and groupings of bits as patterns of light.

Refer to the exhibit. One end of the cable is terminated as displayed, and the other end is terminated in accordance with the T568A standard. What type of cable would be created in this manner?

straight-through Refer to curriculum topic: 4.2.2 A crossover cable has a T568A standard termination at one end and a T568B standard at the other end. A rollover cable can have either a T568A or T568B standard termination at one end, and at the other end have the same standard, but with the wires connected in reverse order. A straight-through cable can have either a T568A or T568B standard termination at one end and the same at the other end. A fiber-optic cable is not terminated using RJ-45 connectors.

What is the purpose of the physical link control field in a data link layer header?

to establish the media link Refer to curriculum topic: 4.4.4 Physical link control, flow control, and congestion control are possible fields that may be found in certain frames. The physical link control field is used to establish the media link. The logical connection control field is used to establish a logical connection between nodes. The flow control field is used to start and stop traffic over the media, and the congestion control field is used to indicate congestion in the media.

Which is a function of the Logical Link Control (LLC) sublayer?

to identify which network layer protocol is being used Refer to curriculum topic: 4.3.1 Defining the media access processes that are performed by the hardware and providing data link layer addressing are functions of the MAC sublayer. The data link layer accepts Layer 3 packets and packages them into data units that are called frames.

When is a wired connection preferred to a wireless connection by an end-user device?

when the end-user device will run an application that requires a dedicated connection to the network Refer to curriculum topic: 4.1.1 Examples of when an end-user device would prefer a wired connection include when the device is not within range of a wireless signal, when the device only has an Ethernet NIC, or when the device requires a dedicated connection because of the performance requirements of the application. A wired connection would be also be required for non-delay tolerant applications.