Business Data Communications and IT
Infrastructures New Edition Test Bank
Media access controls - answers Refer to the need to control when computers transmit.
Data link layer - answers Accepts messages from the network layer and controls the
hardware that transmits them.
Rules or protocols in data transmission - answers Both the sender and receiver need to
be concerned about the rules or protocols that govern how they communicate.
Contention - answers A form of media access control where a computer does not have
to wait before it can transmit; it can transmit at any time.
Polling - answers The process of permitting clients to transmit or receive at specific
times, not at any time.
Roll-call polling - answers A server polls clients in a consecutive, pre-arranged priority
list.
Token passing - answers A term that refers to hub polling, where one computer starts a
poll and passes it to the next computer on a multipoint circuit.
Ethernet local area networks - answers Widely use contention for media access control.
Controlled access MAC approaches - answers Work well in a large network with high
usage.
Commonly used controlled access techniques - answers Include access requests,
access demands, and polling.
Categories of network errors - answers Include lost data and delimited data.
Message corruption - answers Occurs if a computer transmits a message containing
'ABC' and the destination computer receives 'abc'.
Data transmission errors - answers Typically are not distributed uniformly in time.
Undesirable stray electrical voltage - answers Can cause data communication errors.
Gaussian noise - answers Is a special type of attenuation.
Impulse noise - answers Is caused by the thermal agitation of electrons.
,Crosstalk - answers Occurs when the signal transmitted on one circuit or channel
creates an undesired effect in another circuit or channel.
Attenuation - answers Refers to the loss of signal strength.
Intermodulation noise - answers Occurs when the signals from two circuits combine to
form a new signal that falls into a frequency band reserved for another signal.
Physical and data link layers of wired Ethernet - answers Have been refined over the
years as a collection of standards under the IEEE 802.3 workgroup.
Distance between repeaters or amplifiers on a telephone circuit - answers Is determined
by the amount of power gained per unit length of the transmission.
Amplifying the signal on an analog circuit - answers Also amplifies any noise that is
present on the circuit.
Error detection and correction - answers Requires extra error detection 'data' to be
included with each message.
Odd parity-checking scheme - answers Sets the parity bit to make the total number of
ones in the byte an even number.
Parity checking - answers Can only detect an error when an even number of bits are
switched.
Cyclical redundancy check - answers Is one of the most popular polynomial error-
checking schemes.
Simplest method for error correction - answers Is retransmission.
Continuous ARQ - answers Is another term for sliding window.
Forward error correction - answers One type is the Hamming code.
Forward error correction - answers Commonly used in satellite transmission.
HDLC - answers Very similar to the SDLC synchronous data link protocol.
Overhead bits - answers Used for error checking and marking the start and end of
characters and packets.
Transmission efficiency - answers Refers to the percentage of bits transmitted without
errors.
Data link layer - answers Accepts streams of bits from the application layer.
, Data link layer - answers Responsible for encoding the bit-stream as a series of
electronic voltages.
Data link layer - answers Performs error detection.
Data link layer - answers Performs routing functions.
Data link layer - answers Organizes data from the physical layer and passes these
coherent messages directly to the application layer.
Media access control - answers Not very important in point-to-point with full duplex
configuration.
Media access control - answers Not very important in local area networks.
Media access control - answers Not very important in a point-to-point with a half-duplex
configuration.
Media access control - answers Not very important in a multipoint configuration.
Media access control - answers Does not control when computers transmit.
Roll call polling - answers Cannot be modified to increase priority of clients or terminals.
Roll call polling - answers Does not require a server, host, or special device that
performs the polling.
Roll call polling - answers Also called token passing.
Roll call polling - answers A type of contention approach to media access control.
Controlled approaches - answers Work better than contention approaches for large
networks that have high usage.
Contention approaches - answers Generally do not work better than controlled
approaches for all sizes of networks.
Media access control - answers Refers to the methods used to control access to the
media in a network.
Error detection using parity - answers The probability for detecting an error, given that
one has occurred, is about 50% for either even or odd parity.
Error detection probability - answers Using parity, the probability for detecting an error,
given that one has occurred, is about 25% for either even or odd parity.
Infrastructures New Edition Test Bank
Media access controls - answers Refer to the need to control when computers transmit.
Data link layer - answers Accepts messages from the network layer and controls the
hardware that transmits them.
Rules or protocols in data transmission - answers Both the sender and receiver need to
be concerned about the rules or protocols that govern how they communicate.
Contention - answers A form of media access control where a computer does not have
to wait before it can transmit; it can transmit at any time.
Polling - answers The process of permitting clients to transmit or receive at specific
times, not at any time.
Roll-call polling - answers A server polls clients in a consecutive, pre-arranged priority
list.
Token passing - answers A term that refers to hub polling, where one computer starts a
poll and passes it to the next computer on a multipoint circuit.
Ethernet local area networks - answers Widely use contention for media access control.
Controlled access MAC approaches - answers Work well in a large network with high
usage.
Commonly used controlled access techniques - answers Include access requests,
access demands, and polling.
Categories of network errors - answers Include lost data and delimited data.
Message corruption - answers Occurs if a computer transmits a message containing
'ABC' and the destination computer receives 'abc'.
Data transmission errors - answers Typically are not distributed uniformly in time.
Undesirable stray electrical voltage - answers Can cause data communication errors.
Gaussian noise - answers Is a special type of attenuation.
Impulse noise - answers Is caused by the thermal agitation of electrons.
,Crosstalk - answers Occurs when the signal transmitted on one circuit or channel
creates an undesired effect in another circuit or channel.
Attenuation - answers Refers to the loss of signal strength.
Intermodulation noise - answers Occurs when the signals from two circuits combine to
form a new signal that falls into a frequency band reserved for another signal.
Physical and data link layers of wired Ethernet - answers Have been refined over the
years as a collection of standards under the IEEE 802.3 workgroup.
Distance between repeaters or amplifiers on a telephone circuit - answers Is determined
by the amount of power gained per unit length of the transmission.
Amplifying the signal on an analog circuit - answers Also amplifies any noise that is
present on the circuit.
Error detection and correction - answers Requires extra error detection 'data' to be
included with each message.
Odd parity-checking scheme - answers Sets the parity bit to make the total number of
ones in the byte an even number.
Parity checking - answers Can only detect an error when an even number of bits are
switched.
Cyclical redundancy check - answers Is one of the most popular polynomial error-
checking schemes.
Simplest method for error correction - answers Is retransmission.
Continuous ARQ - answers Is another term for sliding window.
Forward error correction - answers One type is the Hamming code.
Forward error correction - answers Commonly used in satellite transmission.
HDLC - answers Very similar to the SDLC synchronous data link protocol.
Overhead bits - answers Used for error checking and marking the start and end of
characters and packets.
Transmission efficiency - answers Refers to the percentage of bits transmitted without
errors.
Data link layer - answers Accepts streams of bits from the application layer.
, Data link layer - answers Responsible for encoding the bit-stream as a series of
electronic voltages.
Data link layer - answers Performs error detection.
Data link layer - answers Performs routing functions.
Data link layer - answers Organizes data from the physical layer and passes these
coherent messages directly to the application layer.
Media access control - answers Not very important in point-to-point with full duplex
configuration.
Media access control - answers Not very important in local area networks.
Media access control - answers Not very important in a point-to-point with a half-duplex
configuration.
Media access control - answers Not very important in a multipoint configuration.
Media access control - answers Does not control when computers transmit.
Roll call polling - answers Cannot be modified to increase priority of clients or terminals.
Roll call polling - answers Does not require a server, host, or special device that
performs the polling.
Roll call polling - answers Also called token passing.
Roll call polling - answers A type of contention approach to media access control.
Controlled approaches - answers Work better than contention approaches for large
networks that have high usage.
Contention approaches - answers Generally do not work better than controlled
approaches for all sizes of networks.
Media access control - answers Refers to the methods used to control access to the
media in a network.
Error detection using parity - answers The probability for detecting an error, given that
one has occurred, is about 50% for either even or odd parity.
Error detection probability - answers Using parity, the probability for detecting an error,
given that one has occurred, is about 25% for either even or odd parity.
