1. Fundamentals of Computer Networks 2010 Table of Contents
Introduction.............................................................................................................................................
3 Requirements:
.........................................................................................................................................
5 Question 1:
..........................................................................................................................................
5 Technology Involved:
...........................................................................................................................
5 Definition and usage:
.......................................................................................................................
5 Methods of high Internet Connection:
..................................................................................................
6 Type of Networks:
...........................................................................................................................
6 Cable, DSL, Satellite & Wireless Internet connection
........................................................................
11 Cable:
............................................................................................................................................
11
DSL:..............................................................................................................................................
12 Type of DSL:
...................................................................................................................................
13 Advantages and disadvantages of DSL
..............................................................................................
15 Satellite
connection:.......................................................................................................................
16 Wireless Internet:
...........................................................................................................................
17 Advantages of
Wi-Fi:.....................................................................................................................
18 Question 2:
............................................................................................................................................
20 Access
Speed:....................................................................................................................................
20
Advantages........................................................................................................................................
21 Disadvantages
...................................................................................................................................
21 Suitability
..........................................................................................................................................
21 ISDN
.................................................................................................................................................
21
-Advantages...................................................................................................................................
22 -Disadvantages
..............................................................................................................................
22 Suitability:
.....................................................................................................................................
22 DSL or
Broadband.............................................................................................................................
23 DSL comes in two forms:
..............................................................................................................
23 Advantages
....................................................................................................................................
23
Disadvantages................................................................................................................................
23 Suitability
......................................................................................................................................
24 1
2. Fundamentals of Computer Networks 2010 The best service that
provides the best
service:...................................................................................
24 Question 3
.............................................................................................................................................
25 The bright side of Wi-Fi Technology
...................................................................................................
25 The bad side of WI-Fi
Technology.....................................................................................................
26 Question 4
.............................................................................................................................................
27 Environment:
.....................................................................................................................................
27 Client devices:
...................................................................................................................................
27 Hardware Requirements
....................................................................................................................
27 Minimum Hardware Requirements
................................................................................................
28 Minimum Software
Requirements:.................................................................................................
29 Security:
........................................................................................................................................
29 Cost:
..............................................................................................................................................
30 Question 5
.............................................................................................................................................
31 DSL safety and security:
....................................................................................................................
31 Regulation:
........................................................................................................................................
31 Question 6
.............................................................................................................................................
32 Question 7
.............................................................................................................................................
33 Advantages and disadvantages of
Wi-Fi.............................................................................................
33 Question 8
.............................................................................................................................................
35 Conclusion:
...........................................................................................................................................
36 Reference:
.............................................................................................................................................
37 2
3. Fundamentals of Computer Networks 2010 Introduction Is a
computer network, mostly get back or referred as a network, it
contain a lot of computers, devices connect together through a
channels that simplification the connection between the users, and
allow to share data or information with users. Networks may be
classified according to a wide variety of characteristics. Network
nowadays can provide to the people many and more things that can be
useful to the whole world like sharing information specific details
and business and this kind of network can be easily to use and work
with, later we will explain to people how can implement a network .
A computer network allows sharing of resources and information
among devices connected to the network. The Advanced Research
Projects Agency ARPA funded the design of the Advanced Research
Projects Agency Network ARPANET for the United States Department of
Defense. It was the first operational computer network in the
world. Development of the network began in 1969, based on designs
developed during the 1960s. For a history see ARPANET, the first
network. Purpose: Facilitating communications. Using a network,
people can communicate efficiently and easily via e-mail, instant
messaging, chat rooms, telephony, video telephone calls, and video
conferencing. Sharing hardware. In a networked environment, each
computer on a network can access and use hardware on the network.
Suppose several personal computers on a network each require the
use of a laser printer. If the personal computers and a laser
printer are connected to a network, each user can then access the
laser printer on the network, as they need it. 3
4. Fundamentals of Computer Networks 2010 Sharing files, data,
and information. In a network environment, any authorized user can
access data and information stored on other computers on the
network. The capability of providing access to data and information
on shared storage devices is an important feature of many networks.
Sharing software. Users connected to a network can access
application programs on the network. 4
5. Fundamentals of Computer Networks 2010 Requirements:
Question 1: Describe the technology involved, giving a clear
indication of methods of high-speed Internet access that is
available. Technology Involved: Definition and usage: The phrase
technology derive from a Latina word is originally contain 2 words
the first word is techno that is mean ART or ACCOPATION second the
LOGY which mean STUDY or SCIENC. Hence the expression of Technology
means or applies for Scientific and knowledge in every field. There
are two reasons to follow scientific knowledge: for the sake of the
knowledge itself and for the practical uses of that knowledge.
Because this second aspect of science affects the lives of most
people, it is more familiar than the first. Knowledge must be
gained, however, before it can be applied, and often the most
important technological advances arise from research pursued for
its own sake. Traditionally, new technology has been concerned with
the construction of machines, structures, and tools on a relatively
large scale. The development of materials for building bridges or
skyscrapers is an example of this, as is the development of the
internal-combustion engine and the nuclear reactor. While such
activities involve all the sciences, from chemistry to nuclear
physics, the overriding goal has been the same to improve the human
condition by finding better ways to deal with the macroscopic
world. Figure 1: things that related to human technology 5
6. Fundamentals of Computer Networks 2010 The dividing line
between what we include in the following list as technology and
what we call science elsewhere in this volume is somewhat
arbitrary. In general, what we have done is this: if a term is
essential to understanding a particular branch of science, it
appears in the list for that science. Thus, atom appears with the
physical sciences, even though an understanding of atoms is clearly
important to the new technology. If, however, the term involves
something that is likely to affect an individual's life, even
though it is not a central concept of a particular branch of
science, it is listed under Technology. Methods of high Internet
Connection: Type of Networks: Local-Area networks (LANs): The
computers are geographically close together that is, in the same
building. A computer network that spans a relatively small area.
Most LANs are confined to a single building or group of buildings.
However, one LAN can be connected to other LANs over any distance
via telephone lines and radio waves. A system of LANs connected in
this way is called a wide-area network WAN. Most LANs connect
workstations and personal computers. Each node individual computer
in a LAN has its own CPU with which it executes programs, but it
also is able to access data and devices anywhere on the LAN. This
means that many users can share expensive devices, such as laser
printers, as well as data. Users can also use the LAN to
communicate with each other, by sending e-mail or engaging in chat
sessions. Figure 2: Local-area networks (LANs) 6
7. Fundamentals of Computer Networks 2010 Wide-area networks
(WANs): The computers are farther apart and are connected by
telephone lines or radio waves. A computer network that spans a
relatively large geographical area. Typically, a WAN consists of
two or more local-area networks LANs. Computers connected to a
wide-area network are often connected through public networks, such
as the telephone system. They can also be connected through leased
lines or satellites. The largest WAN in existence is the Internet.
Figure 3: Wide-area networks (WANs) 7
8. Fundamentals of Computer Networks 2010 Campus-Area networks
(CANs): The computers are within a limited geographic area, such as
a campus or military base. Acronym for campus-area network. An
interconnection of local-area networks within a limited
geographical space, such as a school campus or a military base.
Figure 4: Campus-area networks (CANs) 8
9. Fundamentals of Computer Networks 2010 Metropolitan-area
networks (MANs): A data network designed for a town or city. Short
for Metropolitan Area Network, a data network designed for a town
or city. In terms of geographic breadth, MANs are larger than
localarea networks LANs, but smaller than wide-area networks WANs.
MANs are usually characterized by very high-speed connections using
fiber optical cable or other digital media. Figure 5:
Metropolitan-area networks (MANs) 9
10. Fundamentals of Computer Networks 2010 Home-area networks
(HANs): A network contained within a user's home that connects a
person's digital devices. Short for home area network. A HAN is a
network contained within a user's home that connects a person's
digital devices, from multiple computers and their peripheral
devices to telephones, VCRs, televisions, video games, home
security systems, smart appliances, fax machines and other digital
devices that are wired into the network. Figure 6: Home-area
networks (HANs) 10
11. Fundamentals of Computer Networks 2010 Cable, DSL,
Satellite & Wireless Internet connection Cable: A cable modem
is a device that enables you to hook up your PC to a local cable TV
line and receive data at about 1.5 Mbps. This data rate far exceeds
that of the prevalent 28.8 and 56 Kbps telephone modems and the up
to 128 Kbps of Integrated Services Digital Network ISDN and is
about the data rate available to subscribers of Digital Subscriber
Line DSL telephone service. A cable modem can be added to or
integrated with a set-top box that provides your TV set with
channels for Internet access. In most cases, cable modems are
furnished as part of the cable access service and are not purchased
directly and installed by the subscriber. A cable modem has two
connections: one to the cable wall outlet and the other to a PC or
to a set-top box for a TV set. Although a cable modem does
modulation between analog and digital signals, it is a much more
complex device than a telephone modem. It can be an external device
or it can be integrated within a computer or set-top box.
Typically, the cable modem attaches to a standard 10BASE-T Ethernet
card in the computer. All of the cable modems attached to a cable
TV company coaxial cable line communicate with a Cable Modem
Termination System CMTS at the local cable TV company office. All
cable modems can receive from and send signals only to the CMTS,
but not to other cable modems on the line. Some services have the
upstream signals returned by telephone rather than cable, in which
case the cable modem is known as a Telco-return cable modem. The
actual bandwidth for Internet service over a cable TV line is up to
27 Mbps on the download path to the subscriber with about 2.5 Mbps
of bandwidth for interactive responses in the other direction.
However, since the local provider may not be connected to the
Internet on a line faster than a T-carrier system at 1.5 Mpbs, a
more likely data rate will be close to 1.5 Mpbs. 11
12. Fundamentals of Computer Networks 2010 DSL: Digital
Subscriber Line DSL is a family of technologies that provides
digital data transmission over the wires of a local telephone
network. DSL originally stood for digital subscriber loop. In
telecommunications marketing, the term Digital Subscriber Line is
widely understood to mean Asymmetric Digital Subscriber Line ADSL,
the most commonly installed technical varieties of DSL. DSL service
is delivered simultaneously with regular telephone on the same
telephone line as it uses a higher frequency band that is separated
by filtering. The data throughput of consumer DSL services
typically ranges from 384 KB/s to 20 MB/s in the direction to the
customer, depending on DSL technology, line conditions, and
service-level implementation. Typically, the data throughput in the
reverse direction, i.e. in the direction to the service provider is
lower, hence the designation of asymmetric service, but the two are
equal for the Symmetric Digital Subscriber Line SDSL service.
Figure 7: Kind of DSL 12
13. Fundamentals of Computer Networks 2010 Type of DSL: ADSL:
ADSL uses standard telephone lines to transmit upstream and
downstream data on a digital frequency, which sets these data
streams apart from the analog signals telephones and fax machines
use. Because the ADSL signal is operating on a different frequency,
the telephone can be used normally, even when surfing the Web with
ADSL service. The only requirement will probably be inexpensive DSL
filters on each phone or fax line, to remove any white noise on the
line that might be generated from ADSL service. The asymmetric in
ADSL refers to the fact that the downstream data rate, or the data
coming to your computer from the Internet, is traveling faster than
upstream data, or the data traveling from your computer to the
Internet. Upstream data rates are slower because Web page requests
are fairly miniscule data strings that do not require much
bandwidth to handle efficiently. HDSL: High bit-rate Digital
Subscriber Line, one of the earliest forms of DSL, is used for
wideband digital transmission within a corporate site and between
the telephone company and a customer. The main characteristic of
HDSL is that it is symmetrical: an equal amount of bandwidth is
available in both directions. HDSL can carry as much on a single
wire of twistedpair cable as can be carried on a T1 line up to
1.544 Mbps in North America or an E1 line up to 2.048 Mbps in
Europe over a somewhat longer range and is considered an
alternative to a T1 or E1 connection. 13
14. Fundamentals of Computer Networks 2010 IDSL: IDSL is a
system in which digital data is transmitted at 128 Kbps on a
regular copper telephone line twisted pair from a user to a
destination using digital rather than analog or voice transmission,
bypassing the telephone company's central office equipment that
handles analog signals. IDSL uses the Integrated Services Digital
Network Integrated Services Digital Network Basic Rate Interface in
ISDN transmission code. IDSL is a technology developed by Ascend
Communications now part of Lucent Technologies. IDSL is only one
possible technology in the Digital Subscriber Line approach of
which Asymmetric Digital Subscriber Line or Asymmetric Digital
Subscriber Line is best known and an expedient approach that allows
use of existing ISDN card technology for data-only use. The
differences between IDSL and ISDN are: ISDN passes through the
phone company's central office voice network; IDSL bypasses it by
plugging into a special router at the phone company end. ISDN
requires call setup; IDSL is a dedicated service. ISDN may involve
per-call fees; IDSL may be billed at a flat rate with no usage
charges. VDSL: Very High Speed Digital Subscriber Line transmits
data in the 13 Mbps - 55 Mbps range over short distances, usually
between 1000 and 4500 feet 300 - 1500 meters, of twisted pair
copper wire. The shorter the distance, the faster the connection
rate. As the final length of cable into the home or office, VDSL
connects to neighborhood Optical Network Units ONUs, which connects
to the central office's main fiber network backbone. This
architecture will allow VDSL users to access the maximum bandwidth
available through normal phone lines. 14
15. Fundamentals of Computer Networks 2010 VDSL is currently
going through a standards issue, so it isn't widely deployed yet.
The VDSL alliance favors a line coding scheme based on Discrete
Multitone DMT, a multi-carrier system that is more compatible with
existing ADSL technology. The VDSL coalition favors a line coding
scheme based on Quadature Amplitude Modulation QAM, a
single-carrier system that is less expensive and consumes less
power. Advantages and disadvantages of DSL Advantages: Sometimes we
are always online and can still use the phone line for usual calls.
Your Internet rate is much faster than an ordinary modem 1.5 Mbps
vs. 56 Kbps. Mainly DSL installation does not need new wiring, so
it uses your vacant phone line. It is Up to 25x Times faster than
the Dial-up Modem. The Cost efficient. No eventful Signals. No
Dropped links. Faster to downloads documents. Games are faster to
engage in recreation it online. Devoted Connection & Speed.
15
16. Fundamentals of Computer Networks 2010 Disadvantages: The
DSL connection it works faster if you are existing closer to
provider central office. Data being received is faster than data
being sent over the Internet. DSL accessibility is limited to
certain cities, not each person can get this service. -Access: Is
the most service for using the inter connection for private users
and can be use for the villatic places where cable or DSL is not
available there and cant be implement. And more over satellite is
the best connection for these kinds of places. Satellite
connection: Satellite connection cannot be work by phone line or
cable other by dish. The computer is connecting to a satellite
modem which is correlated to the satellite dish antenna and can be
accusatively on the home roof. When you browse a webpage, your
request is sent to the satellite. The satellite then transmits a
signal to the operation center of satellite internet provider. The
webpage information is then beamed back to your computer through
the same path. Figure 8: Type of Satellite Figure 9: How Satellite
Works 16
17. Fundamentals of Computer Networks 2010 Advantages of
Satellite Internet Access: High speed internet access in rural /
remote areas where cable and DSL are not available. Does not tie up
with local phone service or cable TV subscription. Connection speed
is not affected by phone or cable wiring. Disadvantages of
Satellite Internet Access: More expensive than DSL and cable. Large
setup fee. Expensive equipment upfront. Has to be set up by trained
technician. Short delay of signal transmission may affect real time
applications. Fair access policy limits the ability to download
large files in reasonable amount of time. Connection speed is
slower than DSL and cable. Wireless Internet: Wireless networks
utilize radio waves and/or microwaves to maintain communication
channels between computers. Wireless networking is a more modern
alternative to wired networking that relies on copper and/or fiber
optic cabling between network devices. Wireless is rapidly gaining
in popularity for both home and business networking. Wireless
technology continues to improve, and the cost of wireless products
continues to decrease. Popular wireless local area networking WLAN
products conform to the 802.11 Wi-Fi standards. The gear a person
needs to build wireless networks include network adapters NICs,
access points APs, and routers. 17
18. Fundamentals of Computer Networks 2010 Advantages of Wi-Fi:
Flexible Working: Access the Internet, do File Transfers, even
Print from anywhere within 100 meters of the Wi-Fi Access Point.
Reduce Cable Clutter: Reduce the clutter of wires and cables behind
your Desktop/ Notebook. Reduce Setup Cost: If you are setting up a
new office, you can reduce the IT setup cost by implementing Wi-Fi
- you can save the cost of cabling and the cost on Network sockets.
Avoid Deterioration with Time: Network Cables and Sockets tend to
deteriorate over time, while Wi-Fi does not have this disadvantage.
Eliminate Re-configuring Computers: If you have more than one
office location and your staff travel between offices, installing
Wi-Fi Networks at each location makes good sense. Your staff can
then access the Internet and Network at all locations, without
having to re-configure their Internet settings each time. 18
19. Fundamentals of Computer Networks 2010 Disadvantages of
Wi-Fi: Password and Security: It is important to secure your Wi-Fi
connection at home or the office. Otherwise, anyone with a
Wi-Fi-enabled computer can access your data and Internet connection
Password-protecting your Wi-Fi connection is an easy process and
once you set up all your Computers and devices to access your Wi-Fi
network, you do not need to type in passwords each time thereafter.
Signal Strength Sensitivity: Wi-Fi Networks are sensitive to signal
strength. To ensure good connectivity, you must ensure that all
computers and gadgets receive adequate signal strength at all
times. Effect of Climatic Conditions: Wi-Fi signals are likely to
be adversely affected by climatic conditions such as thunderstorms.
Figure 10: DSL Modem Increased number of Network Devices: You are
increasing the number of devices on your Network, by incorporating
a Wi-Fi Access point this is a must, for Wi-Fi access. Also, you
will need a power socket to plug in and power the Wi-Fi Access
Point. 19
20. Fundamentals of Computer Networks 2010 Question 2: Which
service provides the best service? Which is the cheapest? Justify
your answer. Today an Internet connection is essential not only for
surfing the Internet but for email, music and video downloads and
also for uploading content to your website. Here we will look at
how to choose an Internet connection that's right for your needs.
An Internet connection is provided by an ISP Internet service
provider. There are many ISPs to choose from and a number of
different connection methods. When choosing your internet
connection you need to take into account: Access speed Access type
Always on - broadband, cable and wireless Access Speed: This varies
from 28kbits/sec dial up to 4000 Kbits/sec cable broadband. If you
are just viewing web pages then 28k is acceptable for downloading
or uploading large files like video, music or pictures then it will
be very slow and you need to consider alternatives. With an always
on connection broadband/cable the connection is always established
and it never disconnects. This means that an email sent to you
arrives straight in your inbox without you having to connect to the
Internet and check. Not only does such a connection provide instant
access, it is also faster and easier to share with a large group of
users. I do however mean that your computer/network is permanently
exposed to the Internet and you need to take extra precautions.
Dial-Up Analogue Connection -56K Monthly Cost: Varies from 1p per
minute to 60RM per month unlimited access. Speed: Up to 56Kbps
Hardware Requirements: 56k modem included in most modern PCs
approx. 106-215RM. 20
21. Fundamentals of Computer Networks 2010 Advantages
Inexpensive. Wide availability. Disadvantages Using a modem ties up
a phone line. Connection is not always on. Slowest access method.
Suitability Basic Internet browsing and email. Not suitable if
regularly downloading or uploading large files like music, video or
pictures. If your web site is mainly text based then this type of
connection is ok. If you have a music Website or similar and need
to make music files available then you first need to upload them to
the Internet, then this type of connection is not suitable. ISDN
Similar to dial-up, ISDN establishes a connection to your service
provider when you access the Internet. However, ISDN circuits are
64-128K and fully digital. ISDN is not easy to install and
troubleshoot and requires you to have an ISDN box installed by your
telephone company. It is frequently used by small businesses as in
addition to the ISDN line you can also use a normal telephone line
at the same time. This means you can access the Internet as well as
talking on the telephone. Monthly Cost: As Analogue dial up. Speed:
64Kbps - 128Kbps. Hardware Requirements: ISDN card 30-190 RM or
router 200-300. 21
22. Fundamentals of Computer Networks 2010 -Advantages Lets you
talk and surf simultaneously. Faster than 56kbps analogue. Suitable
for attaching more than 1 PC to the Internet 2-6 light users.
-Disadvantages Difficult to setup. Available only in limited areas.
Requires special termination equipment to be fitted by the telecom
company at both ends of the telephone line. Outdated being replaced
by DSL. Not practical for more than 6 computers depending on usage.
Suitability: Basic Internet browsing and email and connection
sharing. Not suitable if regularly downloading or uploading very
large files like music, video or pictures. If your web site is
mainly text based then this type of connection is ok. If you have a
music Website and need to make many music files available then you
first need to upload them to the Internet, then this type of
connection is not suitable. Cable Cable connects you to the
Internet through a coaxial cable usually using the same line as
your TV service. Cable connections offer very high connection
speeds, 1 to 4 Mbps, but the connection may be shared with other
users. This means that you can experience much slower speeds due to
congestion. Hardware Requirements: Cable Modem Usually included. If
you have multiple computers then you might need cable router to
share connection. Speed: 500 Kbps to 2 Mbps. 22
23. Fundamentals of Computer Networks 2010 DSL or Broadband DSL
Digital Subscriber Line Broadband is a relatively new technology,
which brings high connection speeds to normal analogue telephone
users. It is basically the telecom answer to cable. DSL comes in
two forms: Asymmetrical Digital Subscriber Line ADSL provides
different upload and download speeds most common. Symmetrical
Digital Subscriber Line SDSL provides the same speed in both
directions Monthly Cost: Starts at approx. Speed: 128Kbps - 1Mbps
Hardware Requirements: DSL modem often included. If you want to
connect multiple computers: one DSL router. Advantages Always on
connection. Can use a telephone and Internet simultaneously. Wide
variety of speeds and prices. Large choice of service providers
ISPs. Disadvantages Available only in limited areas Speed vary
widely Some providers have monthly download limits1GB per month is
typical. Requires special termination equipment to be fitted by the
telecom company at both ends of the telephone line. Exposes
computer to Internet so you need to install firewall software.
Windows XP has a built in firewall. 23
24. Fundamentals of Computer Networks 2010 Suitability
Broadband is suitable for very heavy Internet users and multiple
computers small office or home network. If you regularly download
or upload large files like music, video or pictures then this type
of connection is the one you need. The best service that provides
the best service: So, from all the details that mention upper can
say that the all types of service got positive and negative points.
But the best service that users can use is the DSL because is more
faster and can be named under the high-speed category than the
other connection, easy to call while using the internet, and much
cheaper and available that can find it in MALAYSIA and the other
thing about the DSL is easy and cheaper for implement in many
places such as houses, buildings, offices, hospitals, universities,
government buildings, and even under the ground. That what gives
DSL the ability to be the best service that can be providing fast,
secure, cheap, and easy connection for many users to use. 24
25. Fundamentals of Computer Networks 2010 Question 3 Describe
with examples the importance of Wi-Fi technology (i.e. how the
technology has or will affect human beings at work and social
life). WIFI gives you an extremely large amount of freedom because
you can basically use it from anywhere. From your couch to your
local shopping mall, wireless reliability can always lend a helping
hand. Also, WIFI is not restricted to certain groups. No matter who
you are, you can use it. WIFI is fast, reliable, and easy to use.
Wireless Fidelity is important to the wireless LAN world, because
it is securely tested to assure ability of equipment of the same
frequency band and feature. The bright side of Wi-Fi Technology
Technology with its rapid growing speed is influencing old ways of
doing daily affairs. We don't need any more to move around to
handle different tasks and chores since all of them will be done in
a matter of pushing a button located on a remote control. Nobody
can deny that technology has brought comfort to our lives, but
almost all of us confess this fact that technology by itself has
got a lot of deficits that in long term will cause a lot of side
effects either physically or emotionally. This is a fact that
through the multi-media and the wide spread range of webs Internet
the concept of time and distance have been vanished and people can
keep in touch with each other by means of such facilities. The
negative view is the fact that they keep in touch in a virtual
world not natural. Via the webs and mail the emotional feelings and
thoughts cant be transferred. People can convey their attitudes and
thoughts much more effectively when they are close to each other.
25
26. Fundamentals of Computer Networks 2010 The bad side of
WI-Fi Technology One bad effect of technology on life is that with
more technology placing barriers between people, face to face
meetings happen less. This small, simple change leads to a whole
host of very serious problems with society in general. People are
becoming lazier; choosing to stay at home and play video games than
go to a basketball game or get together with friends. On top of
that, the new barriers that are made because of technology gives
those who are most affected by them a decaying sense of pride in
their country. In fact, it is this lack of pride that has spurred
many of the anti-American feelings that are felt and publicized by
people of this very country. Not all technology is bad or evil, but
we do need to be careful that we don't become slaves meaning
obsessed with, not actual slaves to our own creations. Newspapers
and local agencies and music stores have been forced to shut down
since items are available online. 26
27. Fundamentals of Computer Networks 2010 Question 4 Describe
the criteria required for the successful implementation of the
Wi-Fi technology (i.e. the basic requirements such as hardware,
software, skills, cost, etc.). Environment: Provide a description
of the environment where the wireless network will operate. For
buildings, include the floor plan, type of construction, and
possible locations for mounting access points. For outdoor areas,
include satellite images, aerial photographs, or drawings. Walk
through the areas to verify accuracy of these items. Take lots of
photos. In addition to a visible inspection, consider performing an
RF site survey. All of this will capture the environment in a way
that will help designers choose the right technical elements.
Client devices: You should specify the client devices and existing
client radios to ensure the solution accommodates them in the most
effective manner. For example, you could specify that users will
have laptops running Microsoft Vista with integrated 802.11b/g
radios. This provides a basis for deciding on the type of client
radios to specify for other client devices during the design and
whether theres a need to support legacy devices 802.11b/g. Hardware
Requirements If you simply want to connect your laptop to someone
else's 802.11b network, you will need only client card and driver
software at this point, compatible cards cost between 95rm and
319rm. Like most equipment, the price typically goes up with added
features, such as an external antenna connector, higher output
power, a more sensitive radio, and the usual bells and whistles.
Once you select a card, find out what the network settings are for
the network you want to connect to and hop on. If you need more
range, a small Omni directional antenna typically 160RM-319RM can
significantly extend the roaming range of your laptop. 27
28. Fundamentals of Computer Networks 2010 Minimum Hardware
Requirements Wireless routers are network routers that can join
several wireless networks together and also works as a wireless
access point. The most common routers are DSL or cable modem
broadband routers, which connect the local home networks to the
internet. Significance: Wireless routers are useful tools for homes
and businesses. They are popular, in large part, because of the
issues that having a large amount of cables can provide. They are
relatively inexpensive and can be easy to configure, which only
adds to their popularity. Function: Wireless routers can easily
connect computers sharing a network. All that is required for
wireless routers to work is a network and wireless network adapter
cards for the computers. After the wireless router is installed,
the wireless adapter card picks up on the access point and allows
the computer to connect to that network. Types: There are different
types of wireless routers. Routers have different frequencies,
including Wireless-B, which has a maximum raw data of 11 Mbits/s;
Wireless-A and -G, which both have a maximum raw data rate of 54
Mbits/s, but operate on different frequency bands; and Wireless-N,
which has a maximum raw data rate of 300 Mbits/s. Benefits: Due to
the lack of wires, wireless routers can easily connect several
computers without the fear of tangled wires, giving the user more
freedom. Furthermore, holes are often drilled in walls and floors
to connect the wires from a computer to a wired router, which is a
hassle that isn't necessary for wireless routers. 28
29. Fundamentals of Computer Networks 2010 Warning: Although
wireless routers provide users with the freedom to move, the signal
fades the farther away the user travels from the router. Also,
wireless routers aren't as secure as wired routers, since any
individual with a wireless network adapter can connect to the
access point. 1.0 GHz CPU. 256 MB RAM. 20 GB hard drive. 24X CDROM
reader. 14 XGA color LCD display. 1024 x 768 pixel resolution. VGA
output to drive LCD projectors, monitors, displays. 10/100 - base
-T Ethernet, for network/Internet access. Minimum Software
Requirements: Microsoft Windows XP SP2 operating system. Microsoft
Internet Explorer v6.0. Antivirus software up to date virus
definitions. Firewall software. Security: Describe the sensitivity
of the information that will traverse the wireless network. If
possible, cite existing corporate wireless security policies. Youll
likely need to require encryption and authentication of all client
devices. Be sure to give security requirements plenty of thought so
that you design a solution that will protect the companys valuable
resources. 29
30. Fundamentals of Computer Networks 2010 Cost: The price of
set up wireless network depending on the category of design what
the user want and the range of the area what like to cover.
Wireless network less costly way to access internet than cell phone
network. Set up wireless association it almost require router and
wireless card for desktop barely, but the notebook need the
wireless card because the notebook that already has. This is the
major important the user need to purchase it. For that reason if
the user wants to expand the range of wireless network, than he
needs to buy range extender. According to computers shops the price
for router and wireless card is not crossing than 500RM, the
wireless card 100-200 RM and the typical router around 100-25 RM.
30
31. Fundamentals of Computer Networks 2010 Question 5 -Describe
under what circumstances the technology can be implemented i.e. any
special considerations or pre-requisites such as safety, security,
regulation, etc. DSL safety and security: DSL wire safety got a lot
of arrangement to do before using the connection itself and these
are: The users have to be aware to make the wire apparent to
everyone or bare to the sun light. The DSL wire must be cover with
certain warp and not to be bare to any kind of factor denudation.
The most important point in safety is that user has to be very
organized with the wire to be cling on the wall if the wire is
coming from far access point. For a small office with a network,
the most effective and easily maintained solution is to use
unroutable private IP addresses within the network and access the
Internet through a masq, or NAT router. The users can get the
Internet service by simply plugging into a network jack provided by
the office building's Internet service; they may be providing a
private IP address that provides good protection except from people
in the same building. There are certain programs can protect the
network and this kind of program like the firewall and its
especially for the DSL can protect and make the line secured as
well. Regulation: Line can continue even in the presence for the
DSL signals. These asymmetric data rates are suitable for switched
video. Home entertainment and internet browsing application, making
ADSL the target product for the residential and home worker market
segments and the most widespread flavor of DSL. For more
information about the regulation you can visit this website and the
link is below:
http://books.google.com.my/books?id=G9v6u9weUNgC&pg=PA159&dq=Digital+Subscriber+L
ine+regulation&hl=en&ei=bTDLSqmMs6vrAey9LHaCw&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDwQ6AEwAQ#
v=onepage&q=Digital%20Subscriber%20Line%20regulation&f=false
31
32. Fundamentals of Computer Networks 2010 Question 6 -Describe
where such technology is best suited for implementation (i.e. for
specific industry and locality). The best technology can be suited
and implement in the industry places will be the DSL connection
because its fast and cheap to apply it. And the DSL can be connect
to specific place in the industry places because there will be a
problem while implement the DSL inside the factory or working place
so, the perfect idea is to apply the DSL wires to specific points
inside the industry like to the main offices and head section then
from that point we can use another type of network like Wi-Fi
because some of the experts need to use the internet for some
experiments during their work. Unlike the locality the implement of
the DSL will easy to apply inside the buildings because with the
basic of the structure of the building the implement of the DSL
will be easier to apply in different ways and will be more secure
and safety. The most useful thing in DSL in the building especially
in company that its too fast to share information and files between
each other and can create a private network using only by the
company. For the home use the DSL is furthermore great because its
cheap to buy and easy to apply and popular in the whole world and
become a very public. The problem that might face the DSL
connection in the industry is the factory or building which is not
for employers and not organize well, sometime the DSL network need
to setup very well because if there is a problem in send or
receiving data the technical can found the damage point very fast
by making a sign after each point or length thats make fixing the
DSL not that hard. Figure 11: Industry Figure 11: Locality 32
33. Fundamentals of Computer Networks 2010 Question 7 -Describe
the advantages / strengths for implementing Wi-Fi technology.
-Describe the disadvantages / problems for implementing Wi-Fi
technology. Advantages and disadvantages of Wi-Fi Advantages: Wi-Fi
products are extensively available in the market. There are
different brands of access points and user's network interfaces are
able to inter-operate at a very basic service level. The users in
Wi-Fi unlicensed radio spectrum and they are not require regulatory
approval for individual department. The local area network to be
setup with cabling. Prices are considerably lower as competition
amongst vendors' increases. Wi-Fi networks can support roaming.
This allows mobile users with laptop computer to be able to move
from one access point to another. Wi-Fi has a set of global
standards, it is not like the cellular but the users can work in
different countries around the world at the same time.
Disadvantages: The spectrum assignments and operational limitations
are not consistent worldwide. Power consumption is fairly high
compared to some other standards, making the battery life and heat
a concern to some users. Wi-Fi uses the unlicensed 2.4GHz spectrum,
which often crowded with other devices such as Bluetooth, microwave
ovens, cordless phones, or video sender devices, and among many
others. This may cause degradation in performance. Wi-Fi networks
have limited range. A typical Wi-Fi home router might have a range
of 45m 150ft indoors and 90m 300ft outdoors. Ranges may also vary
as Wi-Fi is no exception to the physics of radio wave propagation
with frequency band. 33
34. Fundamentals of Computer Networks 2010 The most common
wireless encryption standard, wired equivalent privacy or WEP has
been shown to be breakable even when it has been correctly
configured. Access points could be used to steal personal and
confidential information transmitted from Wi-Fi consumers.
Intervention of a closed or encrypted access point with other open
access points on the same or a nearby channel can prevent access to
the open access points by others in the area. It poses a high
problem in high-density areas such as large apartment blocks where
many residents are operating Wi-Fi access points 34
35. Fundamentals of Computer Networks 2010 Question 8 Based on
the information you gather, write a plan for subscribing to a
high-speed Internet connection service using relevant diagrams,
figures and provide a simple illustration of the implementation of
the chosen standard. This figure or diagram below show to the user
or person how the network connection build by the formal way. As
you can see in the diagram below the main line its comes from the
main server building which provide the internet service, inside the
main building there is a server which offer the line which is the
server next point will be the central office public phone network
between this two build the user can see that there is a ATM Switch
Asynchronous Transfer Mode, after this two main points the line
will be going to the home or to the destination point inside the
destination point there must be a splitter which can equip two line
in the home one is for the phone as shown below and the other for
the modem. Main building ATM Switch Phone building Server
Destination Splitter DSL Modem HUB 35
36. Fundamentals of Computer Networks 2010 In this condition
the user can choose the wireless modem to offer a wireless
connection network inside the home and for laptops or desktop which
got wireless card, and there is another way if the desktop pc
doesnt have wireless card the user can apply a HUB to connect a LAN
network to the desktop pc as show below as many as the HUB contain
of ports. This kind of connection allows the user to spend little
money and its effective for using the internet, browsing, and
downloading anything from the World Wide Web. And this type can be
found in MALAYSIA as well. Conclusion: Nowadays the internet is
almost in every home and every where in the whole world for this
reason the network can be found in every where and by the time the
people can understand the importance of network and how the
internet and the information transformed. By the time people can
recongnize how the network works and what are the equipment that
being used for implement the set of connection. Moreover the people
are looking for using the internet and network with low cost and
fast transforming details. And the what are the suitable connection
for specific place can be used be powerful without any problem by
arrange this matter verycarefully. 36