Computer Communications
The word ______ refers to the portion of a _______ that carries a transmission. A) channel; link B) link; channel C) line; channel D) line; link
channel; link
RG rating is used in _________ cable. A) twisted-pair B) coaxial C) fiber-optic D) None of the choices are correct
coaxial
In ________ TDM, slots are dynamically allocated to improve bandwidth efficiency. A) synchronous B) statistical C) isochronous D) none of the above
statistical
In ________ TDM, slots are dynamically allocated to improve bandwidth efficiency. A) synchronous B) statistical C) isochronous D) None of the choices are correct
statistical
We need addressing mechanism in ___________ TDM. A) synchronous B) statistical C) both synchronous and statistical D) None of the above choices are correct
statistical
In ________ TDM, each input connection has an allotment in the output even if it is not sending data. A) synchronous B) statistical C) isochronous D) none of the above
synchronous
In ________ TDM, each input connection has an allotment in the output even if it is not sending data. A) synchronous B) statistical C) isochronous D) None of the choices are correct
synchronous
In TCP/IP, a message at the application layer is encapsulated in a packet at the _______ layer.
transport
RJ-45 is a type of connectors used in _________ cabling. A) twisted-pair B) coaxial C) fiber-optic D) None of the choices are correct
twisted pair
UTP and STP are different implementations of ___________________ cable. A) twisted-pair B) coaxial C) fiber-optic D) None of the choices are correct
twisted pair
The session, presentation, and application layers are the ____ support layers. A) user B) network C) both (a) and (b) D) neither (a) nor (b)
user
Which multiplexing technique involves signals composed of light beams? A) FDM B) TDM C) WDM D) PDM
WDM
____ is designed to use the high bandwidth capability of fiber-optic cable. A) FDM B) TDM C) WDM D) None of the above
WDM
____ is designed to use the high bandwidth capability of fiber-optic cable. A) FDM B) TDM C) WDM D) None of the choices are correct
WDM
______ is an analog multiplexing technique to combine optical signals. A) FDM B) TDM C) WDM D) None of the above
WDM
______ is an analog multiplexing technique to combine optical signals. A) FDM B) TDM C) WDM D)
WDM
In TCP/IP, a packet at the third layer carries data belonging to the ________ layer and the header belonging to the _________ layer.
fourth; third
In TDM, the transmission rate of the multiplexed path is usually _______ the sum of the transmission rates of the signal sources. A) greater than B) less than C) equal to D) not related to
greather than
In fiber optics, the signal is _______ waves. A) light B) radio C) infrared D) very low-frequency
light
When a host on network A sends a message to a host on network B, which address does the router look at? A) port B) logical C) physical D) none of the above
logical
In a multiplexed system, __ lines share the bandwidth of ____ link. A) 1; n B) 1; 1 C) n; 1 D) n; n
n; 1
In TCP/IP, a logical connection between an entity at the network layer can be made with another entity at the ________ layer.
network
In TCP/IP, a message at the transport layer is encapsulated in a packet at the ________ layer.
network
In TCP/IP, a message belonging to the transport layer is decapsulated from a packet at the ________ layer.
network
The ______ layer is responsible for the source-to-destination delivery of a packet across multiple network links. A) transport B) network C) data link D) physical
network
The physical, data link, and network layers are the ______ support layers. A) user B) network C) both (a) and (b) D) neither (a) nor (b)
network
IPv6 has _______ -bit addresses. A) 32 B) 64 C) 128 D) variable
128
A port address in TCP/IP is ______ bits long. A) 32 B) 48 C) 16
16
Ethernet uses a ______ physical address that is imprinted on the network interface card (NIC). A) 32-bit B) 64-bit C) 6-byte D) none of the above
6-byte
A T-1 line uses ___________ frames. A) 6000 B) 8000 C) 10000 D) 12000
8000
ICMPv6 includes _______. A) IGMP B) ARP C) RARP D) a and b
A and B
The transport-layer packet in the TCP/IP protocol suite is called
A segment or a user datagram
This was the first network. A) CSNET B) NSFNET C) ANSNET D) ARPANET
ARPANET
As the data packet moves from the upper to the lower layers, headers are _______. A) Added B) Removed C) Rearranged D) Modified
Added
Which of the following is an application layer service? A) Remote log-in B) File transfer and access C) Mail service D) All the above
All of the above
________ is a collection of many separate networks. A) A WAN B) An internet C) a LAN D) None of the above
An Internet
The Internet Protocol (IP) is _____ protocol
An unreliable
Mail services are available to network users through the _______ layer. A) Data link B) Physical C) Transport D) Application
Application
The application layer in the TCP/IP protocol suite is usually considered to be the combination of _____ layers in the OSI model
Application, presentation, session
In the TCP/IP protocol suite, the physical layer is concerned with the movement of _____ over the physical medium
Bits
Which topology requires a multipoint connection? A) Mesh B) Star C) Bus D) Ring
Bus
_______ cable consists of an inner copper core and a second conducting outer sheath. A) Twisted-pair B) Coaxial C) Fiber-optic D) Shielded twisted-pair
Coaxial
The ______ technique expands the bandwidth of a signal by replacing each data bit with n bits using a spreading code. A) FDM B) DSSS C) FHSS D) TDM
DSSS
The ______ technique expands the bandwidth of a signal by replacing each data bit with n bits. A) FDM B) DSSS C) FHSS D) TDM
DSSS
In the TCP/IP protocol suite, the _____ layer is responsible for moving frames from one hop(node) to the next
Data-link
Which agency developed standards for physical connection interfaces and electronic signaling specifications? A) EIA B) ITU-T C) ANSI D) ISO
EIA
________ can be achieved by using multiplexing; ______ can be achieved by using spreading. A) Efficiency; privacy and antijamming B) Privacy and antijamming; efficiency C) Privacy and efficiency; antijamming D) Efficiency and antijamming; privacy
Efficiency; privacy and antijamming
Groups, super groups, master groups, and jumbo groups are terms used in ______________. A) FDM B) DSSS C) FHSS D) TDM
FDM
Which multiplexing technique shifts each signal to a different carrier frequency? A) FDM B) TDM C) Both (a) and (b) D) None of the above
FDM
Which multiplexing technique shifts each signal to a different carrier frequency? A) FDM B) TDM C) WDM D) PDM
FDM
______ can be applied when the bandwidth of a link (in hertz) is greater than the combined bandwidths of the signals to be transmitted. A) TDM B) FDM C) Both (a) or (b) D) Neither (a) or (b)
FDM
The _______ technique uses M different carrier frequencies that are modulated by the source signal. At one moment, the sign modulates one carrier frequency; at the next moment, the signal modulates another carrier frequency. A) FDM B) DSSS C) FHSS D) TDM
FHSS
The _______ technique uses M different carrier frequencies that are modulated by the source signal. At one moment, the sign modulates one carrier frequency; at the next moment, the signal modulates another carrier frequency. A) FDM B) DSSS C) FHSS D) TDM
FHSS
In the TCP/IP protocol suite, which of the following is an application layer protocol
FTP
The Internet model consists of _______ layers. A) Three B) Five C) Seven D) Eight
Five
The TCP/IP protocol suite consists of _____ layers
Five
_______ are special-interest groups that quickly test, evaluate, and standardize new technologies. A) Forums B) Regulatory agencies C) Standards organizations D) All of the above
Forums
In the TCP/IP protocol suite, which of the following is a network-layer protocol
IP
The ____ created a model called the Open Systems Interconnection, which allows diverse systems to communicate. A) OSI B) ISO C) IEEE D) none of the above
ISO
In the TCP/IP protocol suite, a logical address is the identifer ar the _____
Network layer
Which of the following is not an unguided medium? A) twisted-pair cable B) coaxial cable C) fiber-optic cable D) None of the choices are correct
None
Noise in a coaxial cable is reduced by ___________________. A) twisting the cable B) the outer conductor C) the inner conductor D) None of the choices are correct
Outer Conductor
Which multiplexing technique is used for analog signals? A) FDM B) TDM C) WDM D) PDM
PDM
The _______ layer changes bits into electromagnetic signals. A) Physical B) Data link C) Transport D) None of the above
Physical
The _______ layer is the layer closest to the transmission medium. A) Physical B) Data link C) Network D) Transport
Physical
________ is an idea or concept that is a precursor to an Internet standard. A) RCF B) RFC C) ID D) none of the above
RFC
An unauthorized user is a network _______ issue. A) Performance B) Reliability C) Security D) All the above
Security
The OSI model consists of _______ layers. A) three B) five C) seven D) eight
Seven
Which topology requires a central controller or hub? A) Mesh B) Star C) Bus D) Ring
Star
In the TCP/IP protocol suite, which of the following is a transport-layer protocol
TCP
Frame synchronization is a strategy used in ___________. A) FDM B) DSSS C) FHSS D) TDM
TDM
Multilevel multiplexing is a strategy used in ___________. A) FDM B) DSSS C) FHSS D) TDM
TDM
Multislot allocation is a strategy used in ___________. A) FDM B) DSSS C) FHSS D) TDM
TDM
Pulse stuffing is a strategy used in ___________. A) FDM B) DSSS C) FHSS D) TDM
TDM
We can divide ____ into two different schemes: synchronous or statistical. A) FDM B) TDM C) WDM D) None of the choices are correct
TDM
Which multiplexing technique is used for digital signals? A) FDM B) TDM C) WDM D) PDM
TDM
_____ is a digital process that allows several connections to share the high bandwidth of a link. A) FDM B) TDM C) WDM D) None of the choices are correct
TDM
_______ is a process-to-process protocol that adds only port addresses, checksum error control, and length information to the data from the upper layer. A) TCP B) UDP C) IP D) none of the above
UDP
A router is involved in _____ layers of the TCP/IP protocol
Three
The _____ layer is responsible for the delivery of a message from one process to another.
Transport
When data are transmitted from device A to device B, the header from A's layer 4 is read by B's _______ layer. A) Physical B) Transport C) Application D) None of the above
Transport
In the TCP/IP protocol suite, a port number is the identifier at the _____
Transport layer
A link-layer switch is involved in ______ layers of the TCP/IP protocol
Two
FSM is an _________technique. A) analog B) digital C) either (a) or (b) D) none of the above
analog
The _______ layer is responsible for delivering data units from one station to the next without errors. A) transport B) network C) data link D) physical
data link
In TCP/IP, a logical connection between an entity at the data-link layer can be made with another entity at the ________ layer.
data-link
In TCP/IP, a message belonging to the network layer is decapsulated from a packet at the ________ layer.
data-link
The _______ layer changes bits into electromagnetic signals. A) Physical B) Data link C) Transport D) None of the above
physical
The _______ layer coordinates the functions required to transmit a bit stream over a physical medium. A) transport B) network C) data link D) physical
physical
The _______ layer is the layer closest to the transmission medium. A) Physical B) Data link C) Network D) Transport
physical
The ________ address, also known as the link address, is the address of a node as defined by its LAN or WAN. A) port B) physical C) logical D) none of the above
physical
The_____ address identifies a process on a host. A) physical B) IP C) port D) specific
port
To deliver a message to the correct application program running on a host, the _______ address must be consulted. A) port B) IP C) physical D) none of the above
port
In the OSI model, encryption and decryption are functions of the ________ layer. A) transport B) session C) presentation D) application
presentation
The _______ layer ensures interoperability between communicating devices through transformation of data into a mutually agreed upon format. A) transport B) network C) data link D) presentation
presentation
A ________ is a set of rules that governs data communication. A) forum B) protocol C) standard D) none of the above
protocol
In the OSI model, when data is transmitted from device A to device B, the header from A's layer 5 is read by B's _______ layer. A) physical B) transport C) session D) presentation
session
The ______ layer establishes, maintains, and synchronizes the interactions between communicating devices. A) transport B) network C) session
session
In ________, we combine signals from different sources to fit into a larger bandwidth. A) spread spectrum B) line coding C) block coding D) none of the above
spread spectrum
_______ is designed to be used in wireless applications in which stations must be able to share the medium without interception by an eavesdropper and without being subject to jamming from a malicious intruder. A) Spread spectrum B) Multiplexing C) Modulation D) None of the above.
spread spectrum