CHAPTER 12: Networks and Data Communications An Overview

Question 1

The sender and receiver end points, in a communications system, are referred to as

a) hosts.
b) end-users.
c) edge devices.
d) interface devices.

Answer 1

a) hosts.

Question 2

Since data communication is predominantly serial, we usually describe the data as a

a) bit flow.
b) bit surge.
c) byte flow.
d) byte stream.

Answer 2

d) byte stream.

Question 3

To solve the related problems of channel availability and maximum utilization, there must be a way to break long messages into smaller units. These units are called

a) boxes.
b) packets.
c) envelopes.
d) containers.

Answer 3

b) packets.

Question 4

A _________is equivalent to an envelope containing pages of data.

a) packet
b) message
c) segment
d) container

Answer 4

a) packet

Question 5

A direct USB connection between a smartphone and a personal computer is an example of

a) multicast.
b) broadcast.
c) one-to-many connection.
d) point-to-point connection.

Answer 5

d) point-to-point connection.

Question 6

The typical communication channel is actually divided into segments; connections along the segments are called

a) links.
b) routes.
c) dedicated paths.
d) transmission paths.

Answer 6

a) links.

Question 7

The rate of speed with which data can be moved successfully through the channel is usually measured as a

a) bit rate.
b) file rate.
c) block rate.
d) CPU cycle rate.

Answer 7

a) bit rate.

Question 8

Which is not an example of an unguided medium?

a) microwave
b) cellular phone
c) broadcast radio
d) USB connection from computer to smartphone

Answer 8

d) USB connection from computer to smartphone

Question 9

Some channel characteristics are determined innately by the medium. For example, unguided messaging must be carried by an analog signal known as a

a) shipping signal.
b) carrier signal.
c) delivery signal.
d) transport signal.

Answer 9

b) carrier signal.

Question 10

Channels that carry messages in only one direction are known as

a) one-way channels.
b) simplex channels.
c) full duplex channels.
d) half-duplex channels.

Answer 10

b) simplex channels.

Question 11

Channels that carry messages in both directions, but only one direction at a time, are called

a) simplex channels.
b) one-way channels.
c) full-duplex channels.
d) half-duplex channels.

Answer 11

d) half-duplex channels.

Question 12

Channels that carry signals simultaneously in both directions are called

a) simplex channels.
b) one-way channels.
c) full-duplex channels.
d) half-duplex channels.

Answer 12

c) full-duplex channels.

Question 13

A relatively small number of standard protocols, consisting primarily of the _____________ protocol suites, satisfy nearly all of the communication requirements for modern data communication networks.

a) TCP/IP and UDP
b) TCP/IP and BGP
c) TCP/IP and ATM
d) TCP/IP and Ethernet

Answer 13

d) TCP/IP and Ethernet

Question 14

In a __________ topology each computer node gets every message, but processes only those addressed to that node. There is no central hub in this topology.

a) star
b) bus
c) ring
d) mesh

Answer 14

b) bus

Question 15

Which of the following topologies is used primarily for local area networks; all nodes are connected point- to-point to a central device that uses switching technology to connect pairs of nodes together?

a) star
b) bus
c) ring
d) mesh

Answer 15

a) star

Question 16

Which of the following topologies consists of point-to-point connections from each node on the network to the next node; the last node on the network is connected back to the first and there is no central hub?

a) star
b) bus
c) ring
d) mesh

Answer 16

c) ring

Question 17

Which type of topology describes the actual layout of the wiring for the network?

a) virtual
b) logical
c) tangible
d) physical

Answer 17

d) physical

Question 18

Which type of topology defines the operational relationship between the various network components?

a) virtual
b) logical
c) physical
d) tangible

Answer 18

b) logical

Question 19

Which type of network connects computers and other supporting devices over a relatively small localized area, typically a room, the floor of a building, a building, or multiple buildings within close range of each other?

a) LAN
b) CAN
c) WAN
d) Intranet

Answer 19

a) LAN

Question 20

The most familiar, and often most practical and useful, way to categorize networks is by their

a) geographical range of service.
b) medium used (coaxial cable, wireless, fiber).
c) standard specification number (802.3, 802.11, X.25).
d) usage (Web server, database server, peer-to-peer, storage area network).

Answer 20

a) geographical range of service.

Question 21

In a(n) ___________ hub, all of the connections at the hub are simply tied together inside the hub and the hub performs no operation or modification of the signals as they arrive at the hub.

a) active
b) layer 3
c) passive
d) intelligent

Answer 21

c) passive

Question 22

Which Ethernet technology uses radio-based signals to communicate to devices connected on the local area network?

a) Wi-Fi
b) ring Ethernet
c) mesh Ethernet
d) hub-based Ethernet

Answer 22

a) Wi-Fi

Question 23

Which Ethernet type is based logically on a star topology and when one node on the network wishes to communicate with another node, the switch sets up a direct connection between the two?

a) Star Ethernet
b) Ring Ethernet
c) Mesh Ethernet
d) Switched Ethernet

Answer 23

d) Switched Ethernet

Question 24

Each wireless unit is connected by radio to a base station _____________ that is somewhat equivalent to a hub.

a) media site
b) access site
c) media point
d) access point

Answer 24

d) access point

Question 25

Which type of network is used to interconnect local area networks? The primary motivation for this type of network is to improve overall performance of a larger network by creating separate local area networks for groups of users who communicate primarily with each other. a) link networks b) extended networks c) connected networks d) backbone networks

Answer 25

d) backbone networks

Question 26

In a wireless network where the access points are connected by radio, the mesh points operate at the ___________ and are essentially invisible to the upper layers of the network. a) physical layer (layer 1) b) transport layer (layer 4) c) session layer 5 (layer 5) d) media access control layer (layer 2)

Answer 26

d) media access control layer (layer 2)

Question 27

Operation of a metropolitan area network (MAN) generally requires a) access servers. b) peering agreements. c) right of way access. d) fiber optic transmission.

Answer 27

c) right of way access.

Question 28

An access router that is located between the public Internet and the internal LAN is called (a)n a) edge router. b) border router. c) exchange router. d) perimeter router.

Answer 28

a) edge router.

Question 29

Which type of network is designed to facilitate communications between users and applications over large distances—between the various corporate offices of an international organization that are located in cities all over the world, for example. a) LAN b) WAN c) CAN d) MAN

Answer 29

b) WAN

Question 30

Which type of network has ranges of only thirty feet or less, but is sufficient for an individual to interconnect his personal computing devices? a) PAN b) LAN c) WAN d) CAN

Answer 30

a) PAN

Question 31

How might a LAN be designed in a business setting to minimize extraneous traffic where possible? a) Create separate LANs for each floor. b) Create separate LANs for each manager. c) Create separate LANs for each department. d) Create separate LANs for each district or territory.

Answer 31

c) Create separate LANs for each department.

Question 32

What makes virtual circuits more efficient in the use of transmission resources than traditional circuit switching? a) Links and intermediate nodes are shared with other connections. b) A virtual circuit uses multiple links to send data over possibly different channel paths. c) There is a dedicated path for the exclusive use of the sender-receiver pair for the entire time of the connection. d) There is a virtual path for the exclusive use of the sender-receiver pair for the entire time of the connection.

Answer 32

a) Links and intermediate nodes are shared with other connections.

Question 33

Which of the following is not true about datagram switching? a) TCP/IP rarely uses datagram switching. b) Each packet is routed from node to node independently. c) A routing decision can be based on shortest path to next node. d) A routing decision can be based on traffic conditions at the time of packet arrival.

Answer 33

a) TCP/IP rarely uses datagram switching.

Question 34

How do routers and gateways differ? a) Routers are used in ISPs; gateways are used in WANs. b) There are no differences between routers and gateways. c) Routers interconnect dissimilar networks together; gateways connect similar networks. d) Routers connect similar networks together; gateways interconnect dissimilar networks.

Answer 34

d) Routers connect similar networks together; gateways interconnect dissimilar networks.

Question 35

Which of the following is not a major organization that participates in the creation of standards for data communications, networks, and internetworks? a) Internet Engineering Task Force (IETF) b) Association for Computing Machinery (ACM) c) International Organization for Standardization (ISO) d) International Telecommunications Union Telecommunications Group (ITU-T)

Answer 35

b) Association for Computing Machinery (ACM)