Download computer network - CCRI Faculty Web

PowerPoint Presentation to Accompany
Chapter 9
Networks & Communications
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Objectives
1. Discuss the importance of computer networks.
2. Compare different types of LANs and WANs.
3. List and describe the hardware used in both wired
and wireless networks.
4. List and describe the software and protocols used
in both wired and wireless networks.
5. Explain how to protect a network.
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Objective 1: Overview
From Sneakernet to Hotspots
1. Define computer network and network resources
2. Discuss the importance of computer networks
3. Differentiate between peer-to-peer networks and
client-server networks
Key Terms
 Client
 Client-server network
 Computer network
 Homegroup
 Network resource
Visualizing Technology
 Peer-to-peer network
 Server
 Workgroup
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Computer Networks
 A computer network is two or more computers that
share resources
 Network resources can be software, hardware, or
files
 Computer networks save time and money and
increase productivity.
Computer Network Types
A peer-to-peer (P2P)
network is one in
which each
computer is
considered equal.
A client-server
network is one that
has at least one
server at its center.
Computer Network Types
Peer-to-Peer (P2P)
 Each device can
share resources with
Every other device
• No centralized authority
• Each computer belongs to a workgroup
• Do not need to connect to the Internet
• Most found in homes and small businesses
• Simplest type of network
• Do not need network operating system
• All computers must be on to access resources
Peer-to-Peer Networks
 Each node connected to the network can
communicate directly with each other:
 Peers
 Share peripheral
devices:
 Printers
 Scanners
 When printing, a computer on a P2P network
doesn’t have to go through the computer
connected to the printer. It can
communicate directly with the printer
© 2008 Prentice-Hall, Inc.
7
Peer-to-Peer Networks
 Because they are simple to set up, P2P networks are
the most common type of Home network.
 Computers in a P2P network belong to a workgroup.
 This allows you to
share and
remotely access
files on a
Windows network.
© 2008 Prentice-Hall, Inc.
8
Peer-to-Peer Networks
 Most P2P networks are found in homes or small
businesses.
 A peer-to-peer network doesn’t require a NOS.
 While your personal OS has networking features, the
files and services that are shared between your
home computers aren’t centralized.
© 2008 Prentice-Hall, Inc.
9
Peer-to-Peer Networks
 Windows makes setting up a home network an easy
task.
 When you add a new computer to your home and
turn it on, Windows will automatically detect the
other devices that are already on your network.
 Windows Network and Sharing Center enables you
to view and configure your network settings.
 The biggest problem with this type of network is that
the computer that’s sharing a resource must be
turned on and accessible by the other computers in
the network.
© 2008 Prentice-Hall, Inc.
10
Peer-to-Peer Networks
 Windows includes a simple networking feature called
a Homegroup.
 Consists of the computers on your home network
running Windows 7 or higher that are configured
with the same homegroup password.
 Once you create a homegroup, Windows will create
a password that you can use to join all your other
Windows computers to the homegroup.
 Members of a homegroup automatically share their
picture, music, and video libraries and printers with
each other without and additional configuration on
your part.
© 2008 Prentice-Hall, Inc.
11
Peer-to-Peer Networks
 If you have computers running other versions of
Windows or Linux or Mac computers, then you will
need to use a workgroup to share resources
between them.
 Setting up the shares in a workgroup is not difficult
but takes a bit more work than setting up a
homegroup.
 Computers in a workgroup need to have the same
workgroup and account information configured.
© 2008 Prentice-Hall, Inc.
12
Computer Network Types
Client-Server Network
 Has a least one server
at its center
• Provides a way to centralize
network management, resources,
and security
• Users log in to a network and are granted access based
on that login
• A server is a multiuser computer system that runs on a
network operating system
• Clients are the PCs and other devices that connect to
the server
Client/Server Networks
 Most networks with 10 or more nodes are
client/server
 Contains two different types of computers
 Client computers
 Computers on which Users
accomplish specific tasks
and make specific requests
 Server computers
 Computers that provide
information or resources to
the client computers
14
Client/Server Networks
 Server computers
 A multiuser computers system that runs a
NOS and provides central administration for
functions on the network




Printing
E-mail
File
Internet access
© 2008 Prentice-Hall, Inc.
15
Client/Server Networks
 As the name implies, both client software and
server software are needed on a client-server
network.
 The client software makes requests, and the server
software fulfills them.
 A domain is a network composed of a group of
clients and servers under the control of one
central security database on a special server
called the domain controller.
16
Client/Server Networks
 You only need to log in to the domain once to
have access to all the servers in the domain.
 The security database includes your user
information:
 Who you are;
 What your password is;
 What your access and restrictions are.
17
Client/Server Networks
 Clients log in to a server and request access to
resources.
 For many types of servers, a special client is
needed.
 When you use your Web browser to access
your e-mail, it serves as an e-mail client.
18
Client/Server Networks
 The browser can also act as:
 An FTP client when you download a file;
 A database client when you access your bank
transactions;
 An HTTP client when you access a Web page.
 Other client software you may use includes VPN
software, desktop, e-mail programs, instant
messaging/chat programs, and even video and
photo software that include an upload feature
19
Client/Server Networks
 Server software is also known as a network operating
system.
 A network operating system (NOS) is a multiuser
operating system that controls the software and
hardware that runs on a network.
20
Client/Server Networks
 It allows multiple computers (clients) to communicate
with the server and each other, to share resources
and security and provides services such as:
 File and print services;
 Communication services;
 Internet and e-mail services;
 Backup services;
 Database services to the client computers.
21
Client/Server Networks
 Servers are classified by the type of services they
provide.
 Some common services are:
 File and print services;
 E-mail;
 Database;
 Web;
 Chat;
 Audio/video;
 Applications.
22
Client/Server Networks
 The Internet is a Client/Server Network.
 When your computer is connected to the
Internet, it is functioning as a client
computer.
 When connecting to the Internet through
an ISP, your computer connects to a
server computer maintained by the ISP.
 The server “serves up” resources to your
computer so that you can interact with
the Internet
23
Computer Networks
 Computer network
 Two or more
computers
 Share resources
 Save time
 Save money
 Increase productivity
 Network resources
 Software
 Hardware
 Files
 Homegroup
 Simple networking feature
 Used to network a group of Windows computers
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Select a computer network that you use (school,
home, work). Is this a P2P or client-server network?
How do you connect to it? What resources do you
access/share on this network?
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Objective 2: Overview
LANs and WANs
1. Compare different types of networks
2. Differentiate between small and large networks
Key Terms
 CAN
 Cellular network
 Ethernet
 LAN
 MAN
 PAN
Visualizing Technology





SAN
Topology
VPN
WAN
WLAN
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Networks
Small Networks
Large Networks
 LAN: Local area
 PAN: Personal area
 WLAN: Wireless LAN






WAN: Wide area network
VPN: Virtual private network
CAN: Campus area network
MAN: Metropolitan area network
SAN: Storage area network
Cellular networks
Small Networks
 LAN (local area network): A network
that has all connected devices or
nodes located in the same physical
location.



A home network is a peer-to-peer LAN.
A business LAN is more likely a client-server
network and consists of computers, printers,
and servers as well as the network
hardware that connects them.
Devices on a LAN are connected using
switches.
Small Networks
 PAN (personal area network): A LAN
that consists of devices connected by
Bluetooth, such as a PDA and a
computer.



Also called piconet.
Bluetooth is designed to be easy to use,
allowing devices to talk to each other
securely over short distances.
Each device in a piconet can connect to
up to seven other devices at a time.

Mice, keyboards, interactive white boards,
headsets, cell phones, PDAs, cameras, media
players, video game consoles, printers.
Small Networks
 WLAN (wireless LAN): A LAN that uses
WiFi to transmit data.


WiFi has a much larger range, higher
speeds, better security, and supports more
devices than Bluetooth.
More expensive and complicated to set up.
Large Networks
 WAN (wide area network): A network that
spans multiple locations and connects
multiple LANs over dedicated lines using
routers – devices that connect two or more
networks together.



A college that has multiple campuses would
need to use WAN connections between them.
WAN technologies are slower and more
expensive than LAN technologies.
At home, the WAN you connect to is the
Internet, and the port on your router that
connects to the modem is labeled WAN port,
distinguishing it from the LAN ports your other
devices are connected to.
Large Networks
 VPNs (virtual private networks): creates
a private network through the public
network, the Internet, allowing remote
users to access a LAN securely without
needing dedicated lines.


This is much less expensive and more
practical for businesses, and in some cases,
a VPN even replaces the need for
dedicated lines completely.
VPNs use encryption to ensure the data is
secure as it travels through the public
network.
Large Networks
 CAN (campus area network): A hybrid of
LANs and WANs connected using routers.


In a business that is too large and has too many
computers to manage a single LAN practically, there
may be multiple LANs located in the same location.
These LANs are connected to each other using routers,
technically making them WANs.
 MAN (metropolitan area network):
Covers a single geographic area.

A wireless network in Philadelphia provides
access over much of the city.
Large Networks
 SAN (storage area network): Companies
that have massive amounts of
information to move and store have a
network between the data storage
devices and the servers on a network,
making the data accessible to all servers
in the SAN.

Normal users are not part of the SAN but are
able to access the information through the
LAN servers.
Large Networks
 Cellular networks: Use cell towers to
transmit voice and data over long
distances.

Modern 4G networks have speeds that have
made these networks a practical way for
people on the move to connect to network
resources, including the Internet and
corporate VPNs from almost anywhere in the
world.
LAN Topologies
A home LAN uses the same Ethernet standards
and equipment used in larger business
networks.
 Standards – specifications that have been
defined by an industry organization – ensure
that equipment made by many different
companies work together.
 The Ethernet standard defines the way data is
transmitted over a LAN.
 Network data transmission speed is measured
in bits per second.

Ethernet
 Standards are specifications and equipment
used in larger business networks.
 A home LAN uses the same Ethernet standards
and equipment used in larger business networks.
 Ethernet is a standard that defines the way data
is transmitted over a LAN.
 Although there are other network standards, Ethernet is
by far the most widely implemented.
 Standards are important because they assure that
equipment that is made by different companies will be
able to work together.
Ethernet
 Ethernet networks transmit signals over twistedpair cable, fiber-optic cable, and WiFi at data
transmission speeds ranging from 10 Mbps to 10
Gbps.
 The maximum speed depends on the type of media
and capability of the network hardware on the LAN.
 Most home networks use100 Mbps Ethernet.
 Regardless if a small or large network, both use
the same Ethernet standards and equipment
Networks
 The physical layout of a LAN is called its
topology.
 The devices (nodes) on the LAN can be
connected in three physical layouts:
 Bus
 Ring
 Star
Networks



Bus:
 The nodes are all connected via a single cable.
 The data travels back and forth along the cable,
which is terminated at both ends.
Ring:
 The devices are connected to a single cable, but the
ends of the cable are connected in a circle, and the
data travels around the circle in one direction.
Star:
 Every node on the network is attached to a central
device such as a switch or wireless access point.
 This connection device allows nodes to be easily
added, removed, or moved, without disrupting the
network.
Networks
 Computer networks range from two PCs
sharing a printer to large enterprise
networks to the Internet.
 The larger and more complex networks
require more hardware, configuration,
and expertise to manage, but they all
have the same basic purpose – to share
resources.
Make a list of networks that you use. Include home,
cellular, work, and school networks. Label each as
LAN, WAN, or one of the others described in this
article. List the devices you use to connect to each.
What resources do you access?
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Objective 3: Overview
The Networking Hardware Store
1. List and describe the hardware used in wired networks
2. List and describe the hardware used in wireless
networks
Key Terms
 Ad hoc network
 Firewall
 Infrastructure wireless network
 Modem
 Network adapter
 ONT
Visualizing Technology
 Router
 Switch
 WAP
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Hardware Used in Networks
A network adapter is
a communications
device used to
establish a
connection with a
network.
The network hardware
are the physical
devices needed to
create the network.
Network Adapters
WIRED
 Each device that connects
to a network must have
some type of network
adapter.
 Most PCs come with a built-in
Ethernet adapter, also called
RJ-45.


Looks like a slightly larger phone
jack.
The cable used for this type of
connection is called twistedpair, Ethernet cable, or Cat-5 (6).
 The other end of the cable
will plug into a wall jack, a
switch, a router, or a modem
Network Adapters
WIRED
 There are several advantages to using a
wired network connection, including
speed, location, and security.
 Network speed is measured in bits per
second.
 Most home Ethernet connections use
FastEthernet connections, which equal
100Mbps.
 No wireless technology can currently reach
the 1Gbps speed, but some can equal or
exceed the 100 Mbps speed.
Network Adapters
WIRED
 Another advantage is that a wired
connection is less subject to interference
and can travel long distances without
slowing.
 A wireless connection that is 150 Mbps at
close range might drop to less than half
that speed at a distance of 300 feet.
 Buildings and other structures can slow or
even prevent a wireless connection from
working.
Network Adapters
WIRED
 Finally, a wired connection is more secure
than a wireless connection, especially if the
wireless connection is not configured with
strong security settings.
Network Adapters
WIRELESS
 There are several types of wireless network
adapters.
 The Wi-Fi networks found in homes and
public hotspots use the IEEE 802.11
standards.
 The Wi-Fi Alliance certifies wireless devices
to ensure interoperability.
 Most notebook computers and tablets
come with a built-in wireless adapter.
 A USB wireless adapter can easily be
connected to a desktop, smart TV, or
game console that does not have one
built in.
Network Adapters
WIRELESS
 Wireless printers can be connected directly
to a network, eliminating the need to be
shared from an individual computer.
 When two wireless devices connect to each
other directly, they create an ad hoc
network.
 In an infrastructure wireless network, devices
connect through a wireless access point.
 At home, a wireless access point is built
into your wireless router.
Network Adapters
Wired
Wireless
Pros
Cons
1. Maximum speed
1,000 Mbps or 1
Gbps
2. Fast-Ethernet is
100 Mbps
3. Less interference
4. More secure
working
environment
Lack of
portability
Pros
Portability
Cons
1.
2.
3.
4.
Cannot reach the 1
Gbps speed
Prone to
interference
Buildings and
distance can slow or
prevent connection
Needs to be
configured with
strong security
settings
Network Hardware
 A business network consists of routers,
switches, wireless access points, and
firewalls (all in one in a home network).
 The first device on a network is usually the
device that connects to the Internet.



If you use a dial-up connection, this is a
traditional modem (modulator-demodulator).
Cable and DSL have special digital modems.
FIOS has an optical network terminal (ONT).
 You can connect your computer directly
to a modem or ONT, but you can share
the connection with other devices more
easily with some basic network
hardware.
Network Hardware
 A business network consists of routers,
switches, wireless access points, and
firewalls.
 A router is a device that connects two or
more networks together ( your home
network and the Internet).
 A router uses address information to
correctly route the data packets it receives.

In a home network, the router is a convergence
device that serves several functions.
 It shares the Internet connection;
 Provides IP addresses to the other network
devices;
 Provides security for your network.
Network Hardware
 Routers make up the backbone of the
Internet and are responsible for sending
the data packets along the correct route
to their destination.
 Home routers also include a built-in
switch with several ports to connect
multiple devices and can also serve as a
wireless access point.
Network Hardware
 A switch is a device that connects
multiple devices on a LAN and can also
serve as a wireless access point (WAP).
 Within the network, a switch uses address
information to send data packets only to
the port that the appropriate device is
connected to.
Network Hardware
 To set up a WiFi network, you’ll need a
wireless access point.
 A wireless access point (WAP) is a device
that allows wireless devices to join a
network much like a switch.
 It can be built into a router or it can be a
separate device.
 In a large wireless network, there may be
many WAPs installed.
Network Hardware
 A firewall is a device that blocks
unauthorized access to a network.
 There are both hardware firewalls and
software firewalls.

Such as the software firewall included with
your operating system.
 A hardware firewall may be part of a
router or stand-alone device.
Network Hardware
 Firewalls can check both outgoing and
incoming data packets.
 A firewall can be configured with filters to
allow/deny various kinds of traffic.
 Firewall filters can be based on an:
 IP address;
 Protocol type;
 Domain names;
 Other criteria.
 Incoming packets that try to access
restricted data will be denied access to the
network.
Networks
The image shows
a home network
that includes
both wired and
wireless devices.
Network Hardware
 The larger and more complex a network,
the more hardware is necessary to assure
the flow of data.
 These devices work together to transmit
and filter data packets around the
network and eventually to their
destination.
 Without the network hardware,
computers could not connect to each
other.
Open the Network Connections window as described
in this article. What adapters are installed on your
computer? What type of networks do they connect
to? Which of them are connected now? Include a
screen shot in the window.
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Objective 4: Overview
The Softer Side
1. List and describe the software used in both wired and
wireless networks
2. List and describe the protocols used in both wired and
wireless networks
Key Terms
 Domain
 IP
 NOS
 Protocol
 TCP
 TCP/IP protocol stack
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Software Used in Networks
Software and protocols allow networks to
communicate with and understand
each other.
Network operating systems,
communication software, and protocols
make a network work.
P2P Software
 No special software is required to
create a simple P2P network
 Modern desktop OSs have networking
capabilities built into them
 When Windows is installed on a
computer, it includes a feature called
Clients for Microsoft Networks, which
allows it to remotely access files and
printers on a Microsoft network
P2P Software
 Using the workgroup feature of
Windows allows you to share and
remotely access files on a Windows
network.
 OS X includes Windows File Sharing ,
and its network discovery tool should
locate your Windows computer
automatically in Finder.
Client-Server Software
 Both client software and server software are
needed on a client-server network
 The client software makes requests, and the
server software fulfills them
 In a network running Microsoft Server NOS,
Windows clients do not need any special
client software for file and print services
Client-Server Software
DOMAIN CONTROLLER
 They use the same Client for Microsoft Networks
used in peer-to-peer networks to connect to the
servers.
 A domain is a network composed of a group of
clients and servers under the control of one
central security database on a special server
called a domain controller
 You only need to log in to the domain once to
have access to all the servers in the domain
 In a network with multiple servers, you don’t need Io
log in to each one individually.
 The domain security database includes your user
information
 Who you are, what your password is, and what your access and
restrictions are.
Client-Server Software
CLIENT SOFTWARE
For many types of servers, a special client
software is needed.
• When you use a Web browser to access
your e-mail, it serves as an e-mail client
• When you download a file, it acts as an FTP
client
• When you access a database, it acts as a
database client
• When you access a Web page, it acts as
an HTTP client
Client-Server Software
SERVER SOFTWARE
 Server software, also known as a network operating
system (NOS), is a specialized operating system that
controls the software and hardware on a network.
 It allows multiple client devices to communicate with
the server and each other to:
 Share resources;
 Run applications;
 Send messages.
 A NOS centralizes resources and security and provides
services such as file and print services, communication
services, Internet and email services, and backup and
database services to the client computers.
Client-Server Software
SERVER SOFTWARE
 Servers are classified by the type of services they
provide
 Some common services include file and print services,
e-mail, database, Web, chat, audio/video, and
applications
 Whenever you log in to a Web site like Facebook, you
are connecting to a server.
Network Protocols
 Network hardware enables devices to
connect to each other, and network
protocols enable them to
communicate.
 Protocols define the rules for
communication between devices.
 These rules determine how data is
formatted, transmitted, received, and
acknowledged.
 Without protocols, devices could be
physically connected and still unable
to communicate.
Network Protocols
 Network protocols:
 Define how a conversation between
devices begins.
 Define how devices converse
 Define the method to end an electronic
conversation.
Network Protocols
 Although there are hundreds of
different protocols, the most important
ones belong to the TCP/IP protocol
stack
 The basic communication language of the
Internet.
 A suite of protocols that define everything
from how to transfer files (FTP) and
webpages (HTTP) to sending (SMTP) and
receiving (POP) email.
Network Protocols
 TCP stands for Transmission Control
Protocol.
 Responsible for ensuring that data packets
are transmitted reliably.
 IP stands for Internet Protocol.
 Responsible for addressing and routing
packets to their destination.
 Both pieces are needed for data to
move between devices.
Network Protocols
Make a list of networks that you use. Include home,
cellular, work, and school networks. List the software
clients that you use to connect to each. What
resources do you access? Do you use different
clients to access different resources?
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Objective 5: Overview
Protecting Your Network
1. Explain how to protect a network using software,
strong passwords, firewalls, and maintenance
Key Terms
 Piggybacking
 Wardriving
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
Network Protection
Layer 1
Hardware-based firewall via router
Layer 2
Strong passwords
Layer 3
Software-based firewall, antivirus and
anti-malware
Layer 4
Keep system up-to-date and secure
Network Protection
 Layer 1 – The Fence:
 The fence is the hardware at the access
point to your network.
 The firewall examines the data packets as
they enter or leave your network and will
deny access to traffic based on rules the
network administrator defines.
 It also shields your computer from direct
access to the Internet, hiding them from
hackers looking for an easy target.
Network Protection
 Layer 2 – Door Locks:
 Door locks are represented by the network
configuration determining what’s shared
and who’s granted access to it.
 Your usernames should have strong
passwords that are hard to crack.
 Each user should be granted access only
to what they need.
Network Protection
 Layer 3 – Alarm Systems:
 The alarm system includes software-based
firewalls and antivirus and antimalware
software on the individual computers on
the network.
 If an intruder somehow breaches your
network, software will detect unauthorized
actions and prevent them.
Network Protection
 Layer 4 – Guard Dogs:
 The network administrator (you??) needs
to be diligent in keeping the systems on
the network up to date and secure.
 It’s critical that software on PCs is kept up
to date.
 Unpatched systems are easy targets for
hackers and can allow them access into
your network.
Networking Ethics
Piggybacking means
using an open wireless
network connection
to access the Internet
without permission.
Wardriving is the practice of driving around and
locating wireless access points.
List the criteria for a strong password.
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form or by any means, electronic, mechanical,
photocopying, recording, or otherwise, without the prior written permission of the
publisher. Printed in the United States of America.
Copyright © 2014 Pearson Education, Inc.
Publishing as Prentice Hall
Visualizing Technology
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall