Midterm exam Flashcards
What is the binary equivalent of decimal number 75?
1001011
213 to hexa
D5
ED to decimal
237
143 to binary
100011111
187 to hexa
BB
BD to decimal
189
195 to binary
11000011
What is the purpose of the OSI physical layer?
Transmitting bits across the local media
Which characteristics describes crosstalk?
the distortion of the transmited messages from signals carried in adjacent wires
A network administrator is measuring the transfer of bits across the company backbone for a mission application. The administrator notices that the network throuhput appears lower than the bandwidth.
the amount of traffic that is currently crossing the network
Which of the following is a characteristic of fiber-optic cable?
It is not affected by EMI or RFI
What is a primary role of the Physical layer in transmitting data on the network?
create the signals that represent the bits in each frame on the media
With the use of unshielded twisted-pair copper wire in a network, what causes crosstalk within the cable pairs?
The magnetic field around the adjacent pairs of wire
In addition to the cable length, what factor could interfere with the communication carried over UTP cables??
Crosstalk
Which of the following devices commonly affect wireless networks
microwaves
Which of the following statements describe the services provided by the data link layer
a. It defines the end-to-end delivery addressing scheme
b. It maintains the path between the source and destination devices during the data trainsmission
c. It manages the access of frames to the network media
d. It provides reliable delivery through link establishment and flow control
e. It ensures that application data will be transmitted according to the prioritization
C. it manages the access of frames to the network media
Wha 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
What is contained in the trailer of a data-link frame?
error detection
Which statements describes a characteristic of the frame header fields of the data link layer?
They vary depending on protocols
A network team is comparing physical WAN topologies for connecting remote sites to a headquarters building. Which topology provides high availability and connects some, but not all, remote sites?
partial mesh
Which fields or features does Ethernet examine to determine if a received frame is passed to the data link layer or discarded by the NIC
Frame Check Sequence
Which media communication type does not require media arbitration in the data link layer>?
Full duplex
Which statement describes an extended star topology?
a. End devices connect to a central intermediate device, which in turn connects to other central intermediate devices.
b. End devices are connected together by a bus and each bus connects to a central intermediate device.
c. Each end system is connected to its respective neighbor via an intermediate device.
d. All end and intermediate devices are connected in a chain to each other.
a. End devices connect to a central intermediate device, which in turn connects to other central intermediate devices.
What is a characteristic of the LLC sublayer?
a. It provides the logical addressing required that identifies the device.
b. It provides delimitation of data according to the physical signaling requirements of the medium.
c. It places information in the frame allowing multiple Layer 3 protocols to use the same network interface and media.
d. It defines software processes that provide services to the physical layer.
c. It places information in the frame allowing multiple Layer 3 protocols to use the same network interface and media.
What are three ways that media access control is used in networking? (Choose three.)
a. Ethernet utilizes CSMA/CD.
b. Media access control provides placement of data frames onto the media.
c. Contention-based access is also known as deterministic.
802.11 utilizes CSMA/CD.
d. Data link layer protocols define the rules for access to different media.
e. Networks with controlled access have reduced performance due to data collisions.
a. Ethernet utilizes CSMA/CD.
b. Media access control provides placement of data frames onto the media.
d. Data link layer protocols define the rules for access to different media.
During the encapsulation process, what occurs at the data link layer for a PC connected to an Ethernet network?
a. An IP address is added.
b. The logical address is added.
c. The physical address is added.
d. The process port number is added
c. The physical address is added.
What three items are contained in an Ethernet header and trailer? (Choose three.)
a. source IP address
b. source MAC address
c. destination IP address
d. destination MAC address
e. error-checking information
d. destination MAC address
e. error-checking information
b. source MAC address
What type of commuinication rule would best describe CSMA/CD?
Access method
What are the basic parts that are common to all frame types supported by data link layer
- Header
- Data
- Trailer
Which statement is true about the CSMA/CD access method that is used in Ethernet?
a. When a device hears a carrier signal and transmits, a collision cannot occur.
b. A jamming signal causes only devices that caused the collision to execute a backoff algorithm.
c. All network devices must listen before transmitting.
d. Devices involved in a collision get priority to transmit after the backoff period.
c. All network devices must listen before transmitting.
Which frame forwarding method receives the entire frame and performs a CRC check to detect errors before forwarding the frame?
a. cut-through switching
b. store-and-forward switching
c. fragment-free switching
d. fast-forward switching
b. store-and-forward switching
What is the purpose of the FCS field in a frame?
a. to obtain the MAC address of the sending node
b. to verify the logical address of the sending node
c. to compute the CRC header for the data field
d. to determine if errors occurred in the transmission and reception
d. to determine if errors occurred in the transmission and reception
When the store-and-forward method of switching is in use, what part of the Ethernet frame is used to perform an error check?
a. CRC in the trailer
b. source MAC address in the header
c. destination MAC address in the header
d. protocol type in the header
a. CRC in the trailer
Which two statements describe features or functions of the logical link control sublayer in Ethernet standards? (Choose two.)
a. Logical link control is implemented in software.
b. Logical link control is specified in the IEEE 802.3 standard.
c. The LLC sublayer adds a header and a trailer to the data.
d. The data link layer uses LLC to communicate with the upper layers of the protocol suite.
e. The LLC sublayer is responsible for the placement and retrieval of frames on and off the media.
a. Logical link control is implemented in software.
d. The data link layer uses LLC to communicate with the upper layers of the protocol suite.
