Extended Learning Module E – Network Basics
Mod E-1
EXTENDED LEARNING MODULE E
NETWORK BASICS
4. Internet
5. Network Communications Media
6. Network Security
Extended Learning Module E – Network Basics
Mod E-2
LECTURE OUTLINE
INTRODUCTION (p. 409)
1. Basic Principles of Networks
HOME NETWORKS (p. 410)
1. Network Cards in Each Computer
4. Assignments and Exercises
Back to Jump List
Extended Learning Module E – Network Basics
Mod E-3
MODULES, PROJECTS, AND DATA FILES
Group Projects
• Assessing a Wireless Future: Emerging Trends and Technology
• Evaluating the Security of Information: Wireless Network Vulnerability
DATA FILES
There are no data files associated with this module. There may, however, be data files for the
Group Projects you choose to use.
Back to Jump List
Extended Learning Module E – Network Basics
Mod E-4
SLIDE 2
• These are the Student Learning Outcomes for the module.
• Use them as a road map to inform your students of what you will be
covering.
• At the end of the module is a summary of each
SLIDE 3
• These are the Student Learning Outcomes for the module.
• Use them as a road map to inform your students of what you will be
covering.
• At the end of the module is a summary of each.
SLIDE 4
• These are the Student Learning Outcomes for the module.
• Use them as a road map to inform your students of what you will be
covering.
• At the end of the module is a summary of each
SLIDE 5
• This slide defines the term computer network.
• Stress to students that networks come in all sizes from two computers
to share a printer, to the Internet that joins millions of computers
together.
SLIDE 6
• This slide presents the graphic at the bottom of page 409.
• Networks can connect people across a room or across the planet.
Extended Learning Module E – Network Basics
Mod E-5
SLIDE 7
• This slide and the next show the basic principles of networks (Student
Learning Outcome #1).
• This slide has the first three principles and the next slide shows the
fourth.
SLIDE 8
• This slide has the fourth basic principle of networks.
• These principles apply to all networks – great and small.
SLIDE 9
• This slide lists the components you would need to set up a network at
home.
SLIDE 10
• This slide discusses network interface cards.
• The circuit board photo is the expansion card needed if the computer
does not have an NIC built into the motherboard.
• The 3Com box is for a notebook computer, again, only necessary if the
notebook didn’t come with an NIC built in.
SLIDE 11
• This slide discusses Cat 5 cable which is the type of cable usually used
in home and small office networks.
• Cat 5 cable is commonly used for 100 Mbps transmissions and can
support 1Gbps transmissions over short distances
• New installations use Cat 5e or Cat 6 cable, both of which can support
1 Gbps transmissions over greater distances.
Extended Learning Module E – Network Basics
Mod E-6
SLIDE 12
• This slide discusses wireless transmission.
• Older wireless access points (QAPs) use a standard called IEEE
802.11b, which runs up to 11Mbps.
• Newer WAPs use IEEE 802.11g which runs up to 54 Mbps and is
compatible with 802.11b and 802.11a, which also runs up to 54 Mbps
but is not compatible with 802.11b.
• The newest addition, 802.11n runs at a rate of over 100 Mpbs. It is
compatible with 802.11g.
• Wireless access points still need a network cable to connect to the
Internet.
SLIDE 13
• This slide presents broadband or home routers.
• You’ll need one of these to share a DSL or cable modem Internet
connection.
• Most modern broadband routers have built-in switches to connect
several home computers and printers together.
• Many broadband routers also have built-in firewall capabilities to
protect home computers against unauthorized access from the
Internet.
SLIDE 14
• This slide discusses network operating software.
• Stress to your students that for a small home network that Windows
will do the job.
• Remind the students that you have to turn on the sharing to enable
other computers on the network to access files on your computer.
SLIDE 15
• This slide defines a switch.
• Because network transmissions travel between a single sender and a
single recipient, multiple conversations can happen between different
sets of computers at the same time.
• Each message is only delivered to the intended recipient, so
communications on switches are generally private.
SLIDE 16
• They offer all the advantages of switches as well as added security
since they function as a hardware firewall.
Extended Learning Module E – Network Basics
Mod E-7
SLIDE 17
• Routers for businesses tend to be much more complicated than the
home type since they have to be configured with detailed information
about the networks they’re connection and they also need
instructions on how to pass data to other networks.
• In businesses, the router does not perform the task of connecting
computers, switches do that job.
• In home routers, the two functions are combined.
SLIDE 18
Learning Outcome #2).
• This slide discusses LANs.
SLIDE 19
• This is the second slide on networks categorized by distance.
• This one deals with WANs and MANs.
SLIDE 20
• This slide introduces the Internet and begins a section on related
topics (Student Learning Outcome #3).
• The Internet is a vast network of computers all around the world – a
“network of networks.”
• Messages pass from router to router to router until they reach their
ultimate destinations.
• Each router determines whether it’s directly connected to the
recipient and can make final delivery of the message or whether it
needs to pass the message to another router closer to the destination.
SLIDE 21
• This slide discusses bandwidth.
• The bandwidth is the size of the “highway” along which information
moves. The bigger this highway is the faster information can move
from source to destination.
• For the transfer of text, the extra speed is not nearly as noticeable as
the transfer of music, images, or other such heavy files.
• At the time of writing, fast server connections and high-speed campus
backbones run at 1 Gbps and ultra-high-speed backbones run at 10
Gbps.
• This slide is the first of two that discuss networks based on whether
Extended Learning Module E – Network Basics
Mod E-8
SLIDE 22
• This slide presents the different options available when getting an
Internet connection.
• Note the common theme here. You need a modem and a means by
which information travels between you and your Internet provider.
SLIDE 23
• This slide discusses broadband Internet connections.
• Dial-up is the only Internet access method that is not broadband.
• A broadband Internet connection can have one of a range of speeds,
but all are much more than the 56 Kbps which is the best that a dial–
up connection allows.
SLIDE 24
• This slide discusses a telephone or dial-up Internet connection.
• A dial-up modem is in fact a “telephone apparatus for your computer”
in that humans use people telephones and computers use modems.
• Phone lines were designed for voice and not data and therefore were
built for a modulated signal.
• A telephone modem usually comes built into the motherboards of
modern computers.
• The main use for dial-up Internet access these days is lack of other
options.
SLIDE 25
• This slide introduces DSL.
• DSL Internet access also uses phone lines but the data tones are out of
the range that humans can hear and therefore can be split off
separately so that they don’t interfere with conversations.
SLIDE 26
• This slide discusses cable Internet access.
• This is a very popular option for people who have cable TV, but don’t
have access to DSL.
Extended Learning Module E – Network Basics
Mod E-9
SLIDE 27
• This slide discusses the last home Internet access option – satellite.
• It may be more costly than the other options even if you already have
satellite TV since you need a special dish.
• There is considerable difference between upstream and downstream
speed.
SLIDE 28
8
• This slide discusses T1 and DS3 business lines.
• This is a good option for business since the lines carry voice as well.
SLIDE 29
• This slide highlights frame relay and ATM business services.
• Frame relay and ATM provide virtual circuits among office buildings.
• These services also provide aggregation of telecommunications
circuits so that fewer physical lines are needed.
• The business needs only an ultra-fast line to the telecommunications
provider and from there very fast lines reach out to the company’s
branches.
SLIDE 30
• This slide begins a series that compares the Internet connection types
on the basis of advantages and disadvantages.
• The first in the series highlights the two phone line-based Internet
connections – dial-up and DSL.
SLIDE 31
• This second slide in the comparison series discusses cable modems
and satellite modems.
• This slide is the last that deals with the options that are available for
home use.
Extended Learning Module E – Network Basics
Mod E-10
SLIDE 32
• This last slide in the comparison set shows the two business options –
T! and DS3; and Frame relay and ATM.
• These are not used for the home or small business market since the
cost is prohibitive.
SLIDE 33
• This slide discusses Voice over IP.
• This is a way to send voice over data lines, which is the opposite of
dial-up where data moves over voice lines.
• Many businesses are now choosing this option and connecting their
phones to their data lines.
SLIDE 34
• This slide discusses network media – the methods of moving
information from one computer to another (Student Learning
Outcome #4).
• There are two types – wired and wireless.
SLIDE 35
• This slide and the next discuss wired communications media.
• On this slide are twisted-pair phone cable and coax.
SLIDE 36
• This slide discusses optical fiber, the third type of wired media, which
is more difficult to install and is more expensive.
• Optical fiber is the fastest known transmission medium, theoretically
capable of speeds of at least many terabits (trillions of bits per
second).
• Speed limitations of optical fiber currently depend on the ability to
construct equipment that’s fast enough to transmit and receive
signals at each end, not on any limitations of the fiber itself.
• Optical fiber is used for connections between buildings because it’s
immune to damage from lightening strikes. It’s not metallic and
doesn’t conduct electricity.
Extended Learning Module E – Network Basics
Mod E-11
SLIDE 37
• This slide discusses communications methods that don’t involve wires
of any kind, although there may be wires in the overall system.
• All of these, with the exception of Infrared, which uses red light, use
radio waves.
• Different frequencies are used for different distances.
• The longer distance methods need repeaters to strengthen the signal
and keep it going in the right direction.
SLIDE 38
• Bluetooth is used for very short distances.
• It is way to connect and swap information between stationary and
mobile devices.
• The devices include smart phones, desktops, tablets, faxes, GPS’s, and
video game consoles.
SLIDE 39
• Both microwave and satellite data transmission involve the
transmission of information over long distances.
• An example of the use of microwaves includes moving data between
office blocks located in different parts of town.
• An example of satellite is phone connections between the U.S. and
Indonesia.
SLIDE 40
• This slide presents Figure E-10 on page 425
• It depicts an illustration of microwave transmission.
SLIDE 41
• This slide presents Figure E.11 on page 426
• This illustration is of satellite data transmission.
Extended Learning Module E – Network Basics
Mod E-12
SLIDE 42
• This is the first of a series of slides that deal with network security
(Student Learning Outcome #5).
• This slide lists the four basic principles.
SLIDE 43
• This slide discusses the first of the four principles – confidentiality.
• It deals with the issue of keeping unauthorized people from getting
access to information they have no right to.
SLIDE 44
• This slide deals with the second basic principle of security –
authenticity.
• Authenticity is threatened by fraudulent e-mails claiming to be from
your bank and asking you to go to a Web site and enter personal
information that can then be used to access your real banking records.
This practice is called phishing.
• Another threat against authenticity is pharming, which is redirecting
you from a Web site you intended to go to a site you don’t want to
visit.
• It’s also threatened by Web sites that have names which are common
misspellings and typographical errors of popular Web sites.
SLIDE 45
• This slide deals with the third basic principle of network security –
integrity.
• Integrity is threatened by network transmissions that are altered en
route and by faulty server software that allows unauthorized
individuals to modify stored information.
SLIDE 46
• This slide discusses the fourth and final basic principle of network
security – availability.
• Availability can be crucial. For example, a stockbroker online must be
able to process customer buy and sell orders immediately.
• Retailers must have immediate access to records that they need to
provide customer service.
• Availability is threatened by network failures and high volumes of
malicious network traffic intended to disrupt normal communications
and operation.
Extended Learning Module E – Network Basics
Mod E-13
SLIDE 47
• This slide discusses firewalls, intrusion detection systems, and
intrusion prevention systems.
• Firewalls can be added to individual computers or to key points on the
network.
• Intrusion detection systems can be configured for how much they
should report, so activity that might be normal on a college campus
would be considered a problem and reported as such in a banking
network.
SLIDE 48
• This slide highlights encryption and virtual private networks.
• SSL or secure socket layer encryption protects confidentiality.
• Web sites that are running SSL have an s on the end of the “http”
making it “https.”
• A virtual private network encrypts network transmissions between
two endpoints to protect the confidentiality and integrity of their data
communications.
SLIDE 49
• This slide presents Fig E.12 on page 427
• It illustrates the relationships among a firewall and an intrusion
prevention system
SLIDE 50
• This slide discusses malware.
• Malware is a term for any sort of malicious software, although some
experts are beginning to use the term crimeware for the sort of
software developed specifically for fraud or embezzlement.
Back to Jump List
SHORT-ANSWER QUESTIONS (p. 432)
1. What are the 4 basic principles that apply to all networks?
ANSWER: They are that 1. Every network must have a network interface, either built into
the motherboard or on a separate circuit board; 2. A network has a connecting device
such as a switch; 3. Networks have communications media such as cables or radio waves;
and 4. Networks have network operating systems.
Extended Learning Module E – Network Basics
Mod E-14
2. What is an Ethernet card?
ANSWER: A network switch is a device that connects multiple computers into a network,
ANSWER: Bandwidth is the amount of information that a communications medium can
ANSWER: To make a dial-up connection, you need a computer, a phone line, a modem,
ANSWER: Both use the phone line, but DSL is faster and doesn’t tie up the phone line
ANSWER: Frame relay creates virtual circuits that reduce the number of physical lines
ANSWER: Cat 5 cable is used to connect computers and other devices into a network
ANSWER: Bluetooth technology provides entirely wireless connections for all kinds of
ANSWER: A WiFi or Wireless Fidelity or IEEE 802.11b, g or n is a way of transmitting
information in wave form that is reasonably fast and is often used for notebooks.
11. How does a VPN protect confidentiality?
ANSWER: A virtual private network encrypts all communications between two network
endpoints, such as a headquarters and a branch or home office.
Back to Jump List
Extended Learning Module E – Network Basics
Mod E-15
ASSIGNMENTS & EXERCISES (p. 430)
1. What Are the Internet Access Options in Your Area? Write a report on what sort of
Internet connections are available close to you. How many ISPs offer telephone modem
access? Is DSL available to you? Is it available to anyone in your area? Does your cable
company offer a cable modem? If your school has residence halls, does it offer network
connections? Compare each available service on price and extras like a help line, list of
supported computers and operating systems, and people who will come out to your home
and help you if you’re having difficulties. What type of Internet connection do you
currently use? Do you plan to upgrade in the future? If so, to what type of connection? If
not, why not?
DISCUSSION:
• Answers from your students will depend, of course, on where you’re located.
• The point of this exercise it to make sure your students are aware of the options
available to them
• As an added feature to this assignment, ask students to compare what’s available in
their home town compared to their college town.
2. Investigate Building Your Own Home Network. Build your own home network on paper.
Assume you have the computers already and just need to link them together. Find prices
for switches and routers on the Web. Also research Ethernet cards and cables. If you were
to get a high-speed Internet connection like DSL or cable modem, how much would it
cost? Can you buy your own or would you have to rent the modem from the phone or
cable company?
DISCUSSION:
• Your students’ answers could vary based on the hardware specifics that they chose,
but below is a range of prices for all hardware components mentioned.
• At the time of writing you can buy a range of switches that vary in size and
performance. 5-8 port switches usually range in price from about $30 to $50.
• At the moment you can buy a range of routers that vary in size and performance
based on your needs. Four-port routers usually range in price from $20 (after rebates)
to $150, including wireless access.
• There are various makes of Ethernet cards on the market, but they generally cost
somewhere in the region of $5 to $15 for a 100Mbps card and $30-$150 for a 1Gbps
card.
• Cables of various lengths are available at prices in the neighborhood from $3 for 3ft.
cables to $5 for 7 foot cables.
• The cost of a high-speed Internet connection will vary depending on where you’re
located. At the time of writing, cable modems range in price from about $60 to $80.
DSL modems range in price from $90 to $120. Both cable and DSL modems are often
included at no charge with a one-year commitment to Internet service.
Extended Learning Module E – Network Basics
Mod E-16
3. Demonstrate the Impact of Wireless Technology. How many devices do you own or use
that transmit signals (not just computer data) wirelessly? Think of as many as you can, and
make a list showing the different types by signaling used by each device. Don’t forget that
some devices use multiple wireless technologies, like cell phones with both cellular signals
for voice transmissions and Bluetooth for syncing their address books. Hint: Don’t forget
cordless phones, TV and stereo remotes, radios, and portable computers and PDAs with
infrared capability (look for a small, glossy black window somewhere on the edge of the
case). Can any of your devices communicate with each other?
DISCUSSION:
• Your students’ answers will vary based on their individual lifestyles and jobs, but
below is information on a few devices.
• Air traffic control radar: radio (UHF and SHF)
• Automotive remote keyless entry: radio (various frequency bands, including HF,
VHF, and UHF)
• Baby monitor: radio (various bands, including VHF and UHF)
• Bar code scanner: visible light (red)
• Cell phone: radio (UHF) for voice transmissions, infrared or Bluetooth for syncing
address books with PCs
• Cordless phone: radio (HF, UHF, microwave/SHF, and VHF)
• Garage door opener: radio (HF, VHF, and UHF)
• GPS: radio (UHF)
• Medic alert pendants: radio (HF, UHF, SHF, and VHF)
• Motion sensors: infrared, ultrasonic
• Pacemaker recalibration:
• PDA: Bluetooth, infrared, 802.11a/b/g microwave
• People counter at the entrance of retail stores: infrared
• Police traffic radar: radio (UHF, SHF, VHF, infrared)
• Radio: radio (MF, with amplitude or frequency modulation)
• Radio control hobby vehicles: radio (HF, VHF, UHF)
• Remote control for TV, VCR, DVD, video projector: infrared, radio (UHF)
• Television: radio (VHF, UHF)
• Theft prevention at the exit of retail stores:
• Toll road debit system: radio
• Touchless controls in public restrooms: infrared
• Traffic stoplights: visible light (green, yellow, red)
• Voice-actuated toys and appliances: audio
• Walkie-talkie: radio (HF, VHF, family band/UHF)
• Wireless computer networking: 802.11a/b/g/n microwave, some infrared
• XM (satellite) radio: radio (KU/SHF)
Extended Learning Module E – Network Basics
Mod E-17
DISCUSSION:
• This assignment will test how well versed students are in degree requirements.
• The particular courses will depend on your school’s requirements, but usually there’s
general education courses; business core courses; and departmental degree courses.
4. Consider the Importance of Network Security. Write a report about the importance of
computer and network security in your daily life, in terms of the four principles of
computer security. If you have a job in addition to being a student, write about computer
security in your workplace. If you don’t work outside the classroom, write about how
computer security affects you at school and in your personal life. You may be surprised at
how many things you do depend on some aspect of secure computer records and
communications, like banking, grades, e-mail, timesheets, library and movie rental
records, and many more.
DISCUSSION:
• Your students will come up with a variety of answers. Here are examples of daily
activities and their impact the four principles of computer security.
• Banking:
• Banking today is conducted largely by electronic funds transfer. These transfers
generally must be kept confidential to protect customer privacy, and must be
authentic (really from the sending bank) and accurate (integrity) to protect against
fraud. The computers and communications lines used to perform the transfers
must be available and accessible.
• Online account management must be kept confidential (accessible and visible only
to the customer). The login screen must be authentic (really the correct bank’s
Web site), or the customer may enter passwords that a scammer can then use to
access the customer’s real banking information and schedule funds transfers. The
information must be presented with integrity (accuracy), or customers will lose
faith in the financial institution. The online system may depend less on availability,
as customer may accept an occasional inability to access the system.
• Automated teller machines (ATMs) may not require as high a degree of
confidentiality as some other banking transactions, but shouldn’t reveal account
numbers to anyone other than the customer at the machine. Their data
transmissions must be authentic and accurate – a story is circulating about
computer criminals who figured out how to intercept the ATM transmissions and
tell it to give them all of the money it had stored. And the ATMs should be
available around the clock for customer use – but again, customers may be
forgiving of occasional inaccessibility.
5. Find out about Firewalls. Go to the Web and find out about software and hardware
that protects your computer and home network, respectively.
A. If you only have one computer connected to the Internet, then a software firewall
like Zone Alarm will most likely be enough protection from intruders. Find three
Extended Learning Module E – Network Basics
Mod E-18
different firewall software packages on the Web. A good place to start looking would
be the sites that sell anti-virus software. Compare the firewall software on price and
features.
Some sites to try are as follows:
• Symantec at www.symantec.com
• TREND Micro at www.trendmicro.com
• Virus List (a virus encyclopedia) at www.viruslist.com
• McAffee at www.mcaffee.com
firewall. One place to look is at the LinkSys site (www.linksys.com) or any site that
sells computer hardware.
• Immediate Alerts
• Detailed Event Information
• Blocks or Allows Specified Internet Systems
• Hackerwatch.org Integration
• Automatic, 24×7 Online Updates
• Multi-Layered Security
• Privacy Control
• Security Monitor
• Ad Blocking
• Inbound and Outbound Monitoring
• Network Notification
• Identify Intruders
• Protect your data
• Always on Safety
Back to Jump List