Module 4-7 Flashcards
(63 cards)
What is the purpose of the OSI physical layer?
transmitting bits across the local media
Why are two strands of fiber used for a single fiber optic connection?
They allow for full-duplex connectivity.
Which characteristic describes crosstalk?
the distortion of the transmitted messages from signals carried in adjacent wires
Which procedure is used to reduce the effect of crosstalk in copper cables?
twisting opposing circuit wire pairs together
A network administrator is measuring the transfer of bits across the company backbone for a mission critical financial application. The administrator notices that the network throughput appears lower than the bandwidth expected. Which three factors could influence the differences in throughput? (Choose three.)
the amount of traffic that is currently crossing the network
the type of traffic that is crossing the network
the latency that is created by the number of network devices that the data is crossing
What are two characteristics of fiber-optic cable? (Choose two.)
It is not affected by EMI or RFI.
It is more expensive than UTP cabling is.
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 to 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 two factors could interfere with the communication carried over UTP cables? (Choose two.)
crosstalk
electromagnetic interference
Which two devices commonly affect wireless networks? (Choose two.)
cordless phones
microwaves
Which two statements describe the services provided by the data link layer? (Choose two.)
It manages the access of frames to the network media.
It packages various Layer 3 PDUs into a frame format that is compatible with the network interface.
Which statement describes a characteristic of the frame header fields of the data link layer?
They vary depending on protocols.
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
What is contained in the trailer of a data-link frame?
error detection
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 two fields or features does Ethernet examine to determine if a received frame is passed to the data link layer or discarded by the NIC? (Choose two.)
Frame Check Sequence
minimum frame size
Which media communication type does not require media arbitration in the data link layer?
full-duplex
Which statement describes an extended star topology?
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?
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.)
Ethernet utilizes CSMA/CD.
Media access control provides placement of data frames onto the media.
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?
The physical address is added.
What three items are contained in an Ethernet header and trailer? (Choose three.)
source MAC address
destination MAC address
error-checking information
What type of communication rule would best describe CSMA/CD?
access method
A Layer 2 switch is used to switch incoming frames from a 1000BASE-T port to a port connected to a 100Base-T network. Which method of memory buffering would work best for this task?
shared memory buffering
