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Traffic on a network or internet can be divided into two broad categories: elastic and
inelastic.
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One of the things that may happen when network congestion occurs is packets are
discarded.
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SIP is based on an HTTP-like request/response transaction model.
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The frequency is the rate at which the signal repeats.
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The encoding scheme is the mapping from data bits to signal elements.
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With the exception of the repeat-accumulate code, the LDCP code is systematic.
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PCM starts with a continuous time, continuous amplitude signal from which a digital
signal is produced.
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A reservation scheme is an integral part of ATM networks.
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Congestion is only a critical problem for certain types of switched data networks.
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SIP can support any type of single media or multimedia session, including
teleconferencing.
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The sending station must not send frames at a rate faster than the receiving stations can
absorb them.
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DNS allows essentially unlimited levels and uses the comma as the level delimiter in
printed names.
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Hop-by-hop routing does not readily support traffic engineering or policy routing.
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Route selection refers to the selection of an LSP for a particular FEC.
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Modulation does not permit frequency-division multiplexing.
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IMAP always keeps messages on the server and replicates copies to the clients.
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The modulation rate of a signal is the rate, in bits per second, that data are transmitted.
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A hub topology, with a MAC algorithm such as CSMA to control, is appropriate for
ad-hoc LANs.
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An example of a choke packet is the ICMP Source Quench packet.
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There are no fundamental differences among data, voice, and video communications.
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Each packet contains some portion of the user data plus control information needed for
proper functioning of the network.
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Each protocol provides a set of rules for the exchange of data between systems.
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A category of encoding techniques known as multilevel binary addresses some of the
deficiencies of the NRZ codes.
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Secure Shell (SSH) enables the user and the remote server to authenticate each other.
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A key design issue in switched networks is routing.
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Enabling an employee returning from a trip to transfer data from a personal portable
computer to a server in the office is an example of Nomadic access.
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Random routing requires the use of network information.
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A credit scheme is a more effective scheme with an unreliable network service.
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Using two different voltage levels for the two binary digits is a difficult way to transmit
digital signals.
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Another well known application of circuit switching is the PBX.
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Synchronization and interfacing techniques are sufficient by themselves.
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All first and second generation cellular networks provide encryption.
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The syndrome indicates which of the individual parity-check equations do not equal 0.
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The basic building block of any communications facility is the transmission line.
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The designer who seeks robustness does not need to cope with the requirement for
stability.
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The parabolic reflective antenna is a type of antenna used in terrestrial microwave and
satellite applications.
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________ is determined by whether the routing decision is made on a packet or virtual
circuit basis.
A) Place
B) Update timing
C) Decision time
D) VCC
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The ________ time is the time it takes for a bit to traverse the link between source and
destination.
A) relay
B) flow
C) transmission
D) propagation
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_________ is a desirable property for real-time communication.
A) Low overhead in header bits per packet
B) Modest buffer requirements within the network
C) Low jitter
D) All of the above
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The __________ is the reduction, in decibels, to achieve a specified BER of an
error-correcting coded system compared to an uncoded system using the same
modulation.
A) FEC
B) Hamming distance
C) coding gain
D) checksum
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A wireless LAN linked into a wired LAN on the same premises is referred to as a LAN
________.
A) interconnection
B) handoff
C) ad hoc
D) extension
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To support data transfer to and from a cable modem, a cable TV provider dedicates
________ channels.
A) one
B) two
C) four
D) three
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In FDM, because multiple carriers are to be used, each is referred to as a ________.
A) subcarrier
B) channel
C) WDM
D) subscriber
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The ________ code has been specified for the IEEE 802.3 (Ethernet) standard for
baseband coaxial cable and twisted pair bus LANs.
A) Manchester
B) HDB3
C) differential Manchester
D) NRZ
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__________ proposed an approach for the construction of LDPC codes by defining the
LDPC parity-check matrix.
A) MacKay
B) Reed
C) Gallager
D) Neal
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In a(n) ________ there is a cluster of bits in which a number of errors occur, although
not necessarily all of the bits in the cluster suffer an error.
A) error burst
B) single-bit error
C) idle state
D) error detection
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A cellular network uses multiple low power ________.
A) frequencies
B) receivers
C) antennas
D) transmitters
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Third generation wireless communication supports ________.
A) voice but not multimedia data
B) multimedia but not voice
C) multimedia and voice
D) voice but not video
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In the United States, ________ microwave bands have been set aside for unlicensed
spread spectrum use.
A) 2
B) 3
C) 6
D) 4
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A ________ local area network consists of a closed loop of repeaters that allow data to
circulate around the ring.
A) FDDI
B) ring
C) star
D) tree
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__________ codes are among the most powerful cyclic block codes and are widely
used in wireless applications.
A) Parity check
B) B) BCH
C) LPDC
D) Repeat-accumulate
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The guaranteed service is the most demanding service provided by ISA.
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________ focuses on the architecture and techniques for constraint-based path
computation.
A) CCAMP
B) PCE
C) 12vpn
D) Pwe3
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A _________ is a facility that may store previous requests and responses for handling
new requests.
A) cache
B) gateway
C) proxy
D) tunnel
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The ________ is the maximum value or strength of the signal over time; typically this
value is measured in volts.
A) period
B) phase
C) frequency
D) peak amplitude
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The binary 1 represented by the absence of a line signal and the binary 0 by alternating
positive and negative pulses is ________.
A) pseudoternary
B) NRZ-L
C) bipolar-AMI
D) differential Manchester
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Synchronous time division multiplexing can be used with ________ signals.
A) analog
B) digital signals or analog signals carrying digital data
C) digital
D) digital signals carrying digital data
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_________ is a subtype of a membership query message.
A) General query
B) Group-specific query
C) Group-and-source specific query
D) All of the above
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Each label switching router builds a table, called a ________, to specify how a packet
must be treated and forwarded.
A) LIB
B) LSP
C) ECN
D) FEC
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The objective of __________ is to maintain the number of packets within the network
below the level at which performance falls off dramatically.
A) fast restraint
B) traffic management
C) window management
D) congestion control
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In order for data processing devices to communicate certain conventions must be
decided on. These requirements can collectively be termed ________.
A) synchronization
B) transmission systems
C) exchange management
D) flow control
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_________ explicit congestion signaling approaches notify the user that congestion
avoidance procedures should be initiated where applicable for traffic in the same
direction as the received notification.
A) Datagram
B) Dynamic
C) Forward
D) All of the above
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________ multiplexing is commonly used for multiplexing digitized voice streams and
data streams.
A) Time division
B) Frequency division
C) Statistical time division
D) Synchronous time division
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With ________, routing decisions that are made change as conditions on the network
change.
A) fixed routing
B) flooding
C) adaptive routing
D) random routing
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The essence of MPLS functionality is that traffic is grouped into ________.
A) FECs
B) ECN
C) LIBs
D) LSPs
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A form of attenuation known as ________ is when a transmitted signal attenuates over
distance because the signal is being spread over a larger and larger area.
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The place where telephone companies terminate customer lines and locate switching
equipment to interconnect those lines with other networks is the ________.
A) CO
B) ISP
C) POP
D) NAP
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_________ is a common modulation scheme used with OFDM.
A) QPSK
B) FFT
C) IFFT
D) ISI
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Nonselective, or ________, is the type of fading in which all frequency components of
the received signal fluctuate in the same proportions simultaneously.
A) slow fading
B) fast fading
C) diverse fading
D) flat fading
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Circuit switching connections ________.
A) require manual intervention
B) are opaque
C) require one time automated set up
D) are transparent
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________ is aimed at smoothing out traffic flow by reducing packet clumping that leads
to fluctuations in buffer occupancy.
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A ________ is a private network that is configured within a public network in order to
take advantage of the economies of scale and management facilities of large networks.
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__________ has been defined as the process of combining an input signal m(t) and a
carrier at frequency fc to produce a signal s(t) whose bandwidth is (usually) centered on
fc.
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An important design goal for all three generation systems is to limit channel usage to 5
MHz.
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________ control is achieved by retransmission of damaged frames that have not been
acknowledged or for which the other side requests a retransmission.
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The ________ bandwidth of a signal is the width of the spectrum.
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Reed-Solomon is an example of a ________ code.
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An example of _________ signaling is the explicit congestion notification capability
provided in IP and TCP and defined in RFC 3168.
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The _______ is designed to support digital and analog phones and connect to IP-based
networks using VoIP, as well as provide if needed a connection to the public switched
telephone network using traditional technology.
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The ________ connects calls between mobile units, makes connections between a fixed
subscriber to the public network and a mobile subscriber to the cellular network,
assigns the voice channel to each call, performs handoffs, and monitors the call for
billing information.
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The three MAC frame types are control frames, data frames, and ________ frames.
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With ________, a packet is sent by a source node to every one of its neighbors. At each
node, an incoming packet is retransmitted on all outgoing links except for the link on
which it arrived.
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A distinction needs to be made between data rate (expressed in bits per second and
________ rate )expressed in baud when signal encoding techniques are used.
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An application-level firewall may prevent the forwarding of RTP packets.
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Spread spectrum is an important form of encoding for wireless communications.
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The three basic encoding or modulation techniques for transforming digital data into
analog signals are amplitude shift keying, phase shift keying, and ________.
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_______ is a multiplexing technique used with spread spectrum.
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The ________ standards identify a number of categories of cabling and associated
components that can be used for premises and campus-wide data distribution.
Answer:
