Chapter Answers to end-of-chapter questions

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Copyright © 2008 Prentice
-
Hall. All rights reserved.

Instructor’s Manual Materials to Accompany

COMPUTERS ARE YOUR F
UTURE

CHAPTER 8

NETWORKS: COMMUNICAT
ING AND

SHARING RESOURCES

CHAPTER ANSWERS TO E
ND
-
OF
-
CHAPTER QUESTIONS

Matching


1.


network operating system (NOS)

n

2.


network architecture

k

3.


protocols

j

4.


Ethernet

i

5.


Internet protocol

b

6.


peer
-
to
-
peer network

d

7.


routers

f

8.


clients

a


Chapter 8: Networking: Communicating an
d Sharing Resources

Copyright ©
2008
Prentice
-
Hall. All rights reserved.


2

9.


token

e

10.


packets

h

11.


latency

g

12.


bus topology

l

13.


network topology

m

14.


collision

o

15.


node

c

Multiple Choice


1.

Which of the following is
not

a computer network?

a.

local area network (LAN)

b.

leased
-
line area network (L2AN)

c.

wide area network (WAN)

d.

peer
-
to
-
peer network (P2PN)

b





Chapter 8: Networking: Communicating and Sharing Resources

Copyright ©
2008
Prentice
-
Hall. All rights reserved.


3

2.


Which technology enables netw
orks to funnel messages to their correct destination?

a.

circuit switching

b.

packet switching

c.

both a and b

d.

none of the above

c

3.

Which term describes a computer that is connected to a network?

a.

unit

b.

mode

c.

workstation

d.

terminal u
nit

c

4.

To connect to a LAN, a computer must be equipped with which of the following?

a.

network interface card (NIC)

b.

backbone

c.

both a and b

d.

none of the above

a

5.


Which type of network t
opology is centered on a hub?

a.

star

b.

ring

c.

bus

d.

LAN

a



Chapter 8: Networking: Communicating and Sharing Resources

Copyright ©
2008
Prentice
-
Hall. All rights reserved.


4

6.

Which of the following is
not

a LAN topology?

a.

ring

b.

star

c.

hub

d.

bus

c

7.

Which term describes the phenomenon of more than one computer
trying to use the network at the
same time?

a.

contention

b.

competition

c.

communication

d.

congestion

a

8.

Which of the following is a WAN network connection point that enables users to access the WAN
through a local phone call?

a.

po
int of presence (POP)

b.

leased line

c.

permanent virtual circuit (PVC)

d.

frame relay

a

9.

Which of the following is the most popular LAN standard?

a.

ISDN

b.

LocalTalk

c.

Ethernet

d.

Synchronous Optical Network (SONET)

c


Chapter 8: Networking: Communicating and Sharing Resources

Copyright ©
2008
Prentice
-
Hall. All rights reserved.


5

10.

Which of the following is the oldest and most widely used packet
-
switching protocol for WAN
usage?

a.

10BaseT

b.

category 5 (cat
-
5)

c.

X.25

d.

T1

a

Fill

in the Blank

1.

A(n)
___________

links two or more computer
s together to enable data and resource exchange.

network

2.

A(n)
___________

uses direct cables, radio waves, or infrared signals to link computers within a
small geographic area.

LAN or
l
ocal
a
rea
n
etwork

3.

When a PC is connected to a LAN, the PC is called a(n)
___________.

node

4.

A(n)
___________

is a PC expansion board needed to connect a computer to a LAN.

NIC or
network interchange card

5.

With
___________
_______________, an outgoing message is divided into data units of a fixed size
called packets.

p
acket
s
witching

6.

___________

is a set of standards that offers Ethernet speed without wires.

Wi
-
Fi

7.

___________ ____
_______
install, maintain, and support computer networks, interact with users,
handle security, and troubleshoot problems.

N
etwork administrators

8.

In a(n)
___________
______________, the network cable forms a single bus

to which every
workstation is attached.

bus topology


Chapter 8: Networking: Communicating and Sh
aring Resources

Copyright ©
2008
Prentice
-
Hall. All rights reserved.


6

9.

A network uses
___________

(standards) that enable network
-
connected devices to communicate
with each other.

protocols

10.

The hi
gh
-
capacity transmission lines that carry WAN traffic are called
___________.

backbones

11.

___________

defines how one Internet
-
connected computer can contact another to exchange control
and confirmation messages.

TCP or
T
ransmission
C
ontrol
P
rotocol

12.

With a(n)

___________
, file sharing allows users to decide which computer files, if any, are
accessible to other users on the network.

P2PN or
peer
-
to
-
peer network

13.

___________

is the networking system built into every Macintos
h computer.

Local
Talk

14.

A(n)
___________

uses long
-
distance transmission media to link computers separated by a few miles
or even thousands of miles.

WAN or
wide area network

15.

With
__
_________ ___________
, the network creates a physical end
-
to
-
end circuit between the
sending and receiving computers.

circuit switching


Short Answer


1.

Describe a protocol stack and then draw a diagram that shows what
you have described.

In a computer network, a protocol stack is a means of conceptualizing network architecture in which the
various layers of network functionality are viewed as a vertical stack, like the layers of a layer cake, in
computers linked to the
network. When one computer sends a message to the network, the message goes
down the stack and then traverses the network; on the receiving computer, the message goes up the stack.

Chapter 8: Networking: Communicating and Sh
aring Resources

Copyright ©
2008
Prentice
-
Hall. All rights reserved.


7









2.

Explain the difference betw
een peer
-
to
-
peer and client/server networks.

In a peer
-
to
-
peer network, all the computers on the network are equals
,

and there is no file server. Each
computer user decides which, if any, files will be accessible to other users on the network. Although pee
r
-
to
-
peer networks are easy to set up, they tend to slow down with heavy use, and keeping track of all the shared
files and peripherals quickly becomes confusing. For this reason, peer
-
to
-
peer LANs are not suitable for
networks that connect more than one o
r two

dozen computers.

A client/server network consists of one or more file servers, as well as networked workstations. The clients,
wh
ich

are all the computers that can access the server, send requests to the server. The client/server model
works with any

size or physical layout of LAN and does not tend to slow down with heavy use.

3.

How do LANs and WANs differ?

Distance and media are the deciding factors in differentiating these networks f
r
o
m

each other. LANS use
direct

cabling or localized wireless radio or infrared signals to link computers in a small geographic area.
WANs use long
-
distance transmission media, such as phone lines, microwave transmissions, or even
satellites.

4.

Name t
hree types of LAN topologies
,

and describe how each works.

A bus is a network configuration in which the network cable is a single bus or backbone to which each
workstation is connected. The two ends of the bus have special connectors called terminators.

A

star is a network where all other devices are connected to a central device, typically a computer. This
configuration easily allows new users to be added to the network.

A ring is a network design where all devices are connected in a closed loop or ring.
In this network, data only
travels in one direction around the ring.

5.

What is the difference between contention and congestion?

In a computer network, contention is a problem that arises when two or more computers try t
o access the
network at the same time. Contention can result in collisions, which can destroy data. Congestion occurs in a
packet
-
switching network and is a performance interruption that occurs when a segment of the network
experiences
an
overload.

Chapter 8: Networking: Communicating and Sh
aring Resources

Copyright ©
2008
Prentice
-
Hall. All rights reserved.


8

6.

How do
circuit switching and packet switching differ? What are the advantages of each method?

Circuit
-
switching networks create physical end
-
to
-
end circuits between the sending and receiving computers.
This is similar to a telephone connection between two individ
uals. Once a connection is made, this method
allows for rapid communication between the two computers.

A p
acket
-
switching
network
breaks down outgoing message
s

into distinct data units of a fixed size

packets

and transports the packets over various routes
from the sending
computer
to the receiving computer.
When all the packets arrive at the receiving computer, they are rearranged into their original order. Although
this is a slower transmission process, there is no need to wait for a dedicated connection b
etween the two
computers.