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