Ch 4 Qz4 Flashcards
____________ refers to bits that have been changed, in error, from 1 to 0, or vice versa, in a data transmission.
Contracted bits
Polled bits
Inverse multiplexed bits
Flipped bits
Bit delineation
Flipped bits
Transmission efficiency refers to the percentage of bits transmitted without errors.
True
False
False
In communication protocols, _________ are used to convey the user’s meaning.
information bits
overhead bits
stop bits
start bits
flag bits
information bits
In a network, the type of errors caused during data transmission can be controlled by the network hardware and software.
True
False
True
Gaussian noise is a special type of attenuation.
True
False
False
Forward error correction is commonly used in satellite transmission.
True
False
True
In data transmission, data errors are uniformly distributed in time.
True
False
False
Undesirable stray electrical voltage can cause data communication errors.
True
False
True
Token passing is a term that refers to hub polling, in which one computer starts a poll and passes it to the next computer on a multipoint circuit.
True
False
True
_______ is the process of sending a signal to a client that gives its permission to transmit or asks it to receive.
Contention
Polling
Pooling
Carrier sense
CRC
Polling
Which of the following is not an error detection method used in the data link layer?
parity checking
cyclic redundancy checking
CRC-32
pulse code checking
odd parity
pulse code checking
Which of the following is true with respect to the data link layer?
It accepts streams of bits from the application layer.
It is responsible for getting a message from one computer to another (one node to another) without errors.
It does not perform error detection.
It performs routing functions.
It organizes data from the physical layer and passes these coherent messages to the application layer.
It is responsible for getting a message from one computer to another (one node to another) without errors.
Which of the following is way to reduce or eliminate crosstalk on a circuit,
changing multiplexing techniques
adding repeaters or amplifiers to a circuit
reducing the length of the cable
adding fluorescent lights
shorting a circuit
changing multiplexing techniques
In ARQ, a NAK:
is sent by the recipient if the message was received without error
is sent by the sender at the same time as it sends a data packet
is sent by the recipient if the message contains an error
refers to non-asynchronous Kermit technique
means that the sender should continue with sending the next message
is sent by the recipient if the message contains an error
Which of the following is true about the data link protocol, PPP?
it is commonly used in WANs
it is a bit-oriented protocol
it uses block check characters for error detection
it was developed in the 1970s
it uses parity bits for error detection
it is commonly used in WANs
