Basic of network security, internet connection & Sharing

1. Chapter 3:
Basic of network security,
internet connection &
Sharing
Assi. Prof. Sejal Jadav

2. Q: Give the Importance of Network Security
● We live in an age of information.
Businesses these days are more digitally advanced than
ever, and as technology improves, organizations’
security must be enhanced as well.
Now, with many devices communicating with each other
over wired, wireless, or cellular networks, network
security is an important concept.
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3. ● With a Network Security System, all the
files, data & personal information are
kept safe and protected from
unauthorized access from people present
on the network and people outside it.
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4. ● the reason why it is widely used in offices, banks, and
many other organizations.
● The policies of Network Security help the network
administrator to monitor any kind of misuse,
modification or unauthorized access of a computer
network.
● Thus, a number of cyber attacks and other harmful
activities are prevented.
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5. ● Network Security helps in protecting personal data of
clients existing on network.
● Network Security facilitates protection of information
that is shared between computers on the network.
● Hacking attempts or virus / spyware attacks from the
internet will not be able to harm physical computers.
External possible attacks are prevented.
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6. What is Information
Security?
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7. ● The information security is all about company’s data and
this information can be separate into different parts like
confidentiality, integrity, availability, and authentication.
● These four combined called as Information Security.
I have the below simple definition for it.
Information security =
Confidentiality + Integrity + Availability + Authentication
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8. Confidentiality:
● The most important for network security is
confidentiality without this there is no word for
security.
● It ensures that no unauthorized users can copy, or
replicate the information of the organization.
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9. Integrity:
● As confidentiality, the integrity is necessary so
that the organization has enough confidence in
the accuracy of the information to act upon the
particular issue in the organization.
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10. Availability:
● Information Security requires organizations to be able
to retrieve data and moreover the security measures
are worthless if the organization cannot access to
vital information they need to operate when they
need it.
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11. Authentication:
● To secure data of an organization, there should be a
proper logins ... If information is not secure without
authentication.
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12. Q: give the basic terminology in network security.
● There are many basic terminology that used in
network security.
1)Threats:
● threats are anything that are capable of acting against
an asset in a manner that can result in harm.
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13. Vulnerabilities:
● a vulnerability is a weakness which allows an attacker
to reduce a system's information assurance.
● hardware and software systems designs of are some
time very poor, some time the installation and
configuration is poor and some time poor management
is also responsible for vulnerabilities.
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14. 3)Physical Vulnerabilities:
● In this network equipment like routers and switch,
server should be kept in safe place with restricted Access.
● Also backup should be store in secure area from where
only authorized person can access.
● Organization should also take care of natural
environment like earthquakes, fire, floods etc..
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15. 4)Media Vulnerabilities:
● Disk, tape and other backup should be store in secure
area from where only authorized person can access.
5)Human Vulnerabilities:
● Sometime stupidity, carelessness, laziness of human
damage the system .
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16. 6)Hardware & software:
● Design flow of hardware and software can also breaks
security, sometime older versions of software and
hardware.
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17. Q: give the top five fundamental of network security
 Keep patches and updates current
● When administrators are careless about applying
patches and updates, cyber criminals exploit all
possible Vulnerabilities.
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18. ● In particular, verify that office computers are running current
versions of these much used programs:
1. Adobe Reader
2. Adobe Flash
3. Oracle Java
4. Microsoft Internet Explorer
5. Microsoft Office Suite
● Make sure you keep an inventory to make sure ALL your devices
are updated regularly.
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19. Use Strong Passwords
● Your password should be at least 6 characters and
uses a combination of upper- and lower-case letters,
numbers and symbols.
● This should go without saying: they should be kept
out of sight and only shared with trusted employees
who need them.
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20. ● The SANS Institute also recommends that passwords
be changed every few months at least, without
duplicates.
● Note: (SANS stands for Sys. Admin, Audit, Network
and Security.)
● The SANS Institute is a private U.S. for-profit company
founded in 1989 that specializes in information
security, cybersecurity training and selling
certificates.
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21.  Actively manage user access privileges
● When an employee’s job changes, make sure the IT
department is notified so their access privileges can
be modified to fit the duties of the new position.
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22. Secure your VPN
● You want the strongest possible protocols for
encryption and authentication to protect your
network/data from hackers while your information is
traveling over the Internet.
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23. Q: Explain CCTV Technologies.
● CCTV stands for close Circuit TV.
● CCTV can provide your home or small business with
enhanced security, maintaining an around-the-clock
surveillance to guard against theft and other
potential crimes.
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24. ● Marie Van Brittan Brown was the inventor of the
CCTV camera.
● These CCTV monitoring systems have proven to be
highly beneficial as they are used in deterring
potential criminals, monitoring of employees in an
organization, etc.
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25. ● They are now hugely in use in India and there are
various types of CCTV
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26. 1. Box CCTV Camera
● As the name suggests, these are types of CCTV systems that are
larger in size.
● They are also available in different resolutions and are best for use
in super markets, shops, banks, factories, etc.
● Most of the latest models are highly durable(solid) and easy to
operate. Prices range from Rs. 3,000 to Rs. 8,000.
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27. ● Box CCTV
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28. Dome Camera
● Being dome-shaped, these CCTV systems are smaller than the box
types of CCTV.
● The camera is placed inside a curved dome and is installed in the
ceilings. They are quite difficult to repair.
● The only disadvantage of dome CCTV systems is that they
are unsuitable for long distance monitoring.
● This type of CCTV system can cost around Rs. 8,000 or more based
on the resolution.
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29. ● Dome Camera
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30. Bullet Cameras
● Shaped like a rifle bullet, these cameras are best suited for
monitoring during the night.
● They can be easily mounted on both walls and ceilings.
● they are smaller in size they offer a clear vision which is an
advantage.
● Another advantage is that the bullet CCTV price amounts around
justRs.4, 000 per piece.
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31. ● Bullet Cameras
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32. Spy Cameras
● CCTV systems that are hidden are usually called spy cameras which
are used for security purposes to track criminals.
● They are usually wireless and this types of CCTV cameras they
are fitted in pens, glasses, etc.
● The spy CCTV price begins from as low as Rs. 1,600 up to Rs.
10,000 depending upon the quality and features.
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33. ● Spy Cameras
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34.  Vehicle Plate Recognition Camera
● These are high-speed closed circuit cameras that are
meant for capturing the registration numbers of
stationary vehicles as well as those on the move.
● Based on a software program for the purpose, the
identification of the number is done.
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35. ● The intelligent traffic modes are designed such that the
camera detects the speed and headlight issues of the
vehicle.
● The vehicle plate recognition CCTV price begins from Rs.
20,000.
● There are many manufacturers in India like Sony,
Panasonic, and Samsung that offer these types of CCTV
systems for your use.
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36. Vehicle Plate Recognition Camera
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37. Basic of Internet
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38. Q: Give the brief History of Internet.
● It was developed by DOD [Department of Defense] of
USA military.
● ARPANET was developed in 1969 by ARPA [Advance
Research Project Agency] at the headquarters of USA
military.
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39. ● Its basic purpose was to create a method for widely
separated computers to transfer information
efficiently.
● It was limited for USA military.
● In 1980 USA government organization NSF [National
Science Foundation] has established another network
named NSANET.
(The National Science Foundation Network )
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40. ● which was connecting all universities & various
research center networks.
● Later with the advance technology such network
of networks was grown up to thousands of
regional networks that connect millions of users.
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41. The Internet
● It can be described as “Network of Networks”.
● It is called network of networks because there are
actually many different network systems accessible
through the internet.
● Internet lets you communicate, share data, and share
resources with people around the world.
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42. ● The biggest advantage of internet is that it is a tool
providing access to worldwide quantities of
information.
● Sometimes it is simply called “the Net” in which user
at any one computer can get information from any
other computer, if he has permission.
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43. Q: What is WWW?
● The World Wide Web (WWW) or web for short
is a software application that allows you to
access information on any computer, world-
wide, that makes files publicly available using
hypertext transfer protocol (HTTP).
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44. ● It is called a “WEB” because the interconnection
between documents resembles a spider’s web.
● A central idea in the development of the web was the
Uniform Resource Locator.
● A URL is a Web address that uniquely identifies a
document on the web.
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45. ● Such a document can be image, an HTML file, a
program, etc.
● Main Elements of Web is :
1) Web Server
2) Web Client/ Web Browser
3) Web Page
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46. Generic Domain:
● The top level names are called the generic top-level
domains, and can be three characters or more in
length. (like… .gov, .com , .edu, etc…)
● Below table shows some of the top level domain .
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47. 47

48. Country Domain:
● There are also top-level domains named for the each
of the ISO 3166 international 2-character country
code. (like…. .in , .us , ect…)
● These are called the country domains or the
geographical domains.
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49. Q: Give the Requirement of Browser.
● A web browser or web client is a computer program
that request web resources from web servers on the
internet.
● A web browser is one of many software applications
that function as the interface between a user and the
Internet.
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50. ● Popular browsers include Netscape Navigator,
Microsoft’s Internet Explorer, Mosaic and Lynx.
● The first few are graphical based web browsers,
whereas Lynx is a text only browser.
● This makes Lynx very fast.
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51. ● graphics often cause Web pages to load more slowly.
● More recent browsers like Opera and New Planet are
making talk widely in the market owing to their
charming interface
and number of miscellaneous functionalities they
provide.
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52. ● The browser not only sends messages to web servers
to retrieve you page requests,
but also sends the HTML code once it arrives. That is the
browser interprets code and displays the result on the
screen.
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53. GPS
Global Positioning
System
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54. Q: Explain GPS.
● The GPS is a space-based satellite navigation system
that provides location and time information in all
weather conditions, anywhere on or near the Earth.
● The system provides important capabilities to
military, civil and commercial users around the world.
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55. ● It is maintained by the United States government and
is freely accessible to anyone with a GPS receiver.
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56. ● The GPS project was developed in 1973.
● GPS was created and realized by the U.S. Department
of Defense (DoD)
and was originally run with 24 satellites.
It became fully operational in 1994.
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57. ● A GPS receiver calculates its position by precisely
timing the signals sent by GPS satellites high above
the Earth.
● Each satellite continually transmits messages that
include the time the message was transmitted
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58. ● The receiver uses the messages , it receives to
determine the transit time of each message and
computes the distance to each satellite using the
speed of light.
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60. 60

61. 61

62. How GPS Works
● GPS satellites circle the earth twice a day in a very
precise orbit and transmit signal information to earth.
● GPS receivers take this information and use
triangulation to calculate the user’s exact location.
● The GPS receiver compares the time a signal was
transmitted by a satellite with the time it was
received.
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63. ● The time difference tells the GPS receiver how far
away the satellite is.
● A GPS receiver must be locked on to the signal of at
least three satellites to calculate a 2D position and
track movement.
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64. ● With four or more satellites in view, the receiver can
determine, the user’s 3D position.
● GPS tracker uses radio signals to locate the position.
● Then a software use to tell us about the location in
real times with landmarks, street name and every
single details about the location of the object or
individual.
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65. Application of GPS or Used of GPS:
● Agriculture
● Aviation
● Space
● Timing
● Environment
● Public safety & disaster relief
● Rail
● Marine
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66. Q- What is Firewall ?
● Firewall are just a modern adaption of that old security
● Fire wall is divided into two categories
1) Hardware firewall
2) Software firewall
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67. ● Network layer firewall is a type of firewall that works
as a packet filter by deciding what packets will pass
the firewall according to rules defined by the
administrator.
● Filtering rules can act on the basis of source and
destination address and on ports, in addition to
whatever higher-level network protocols the packet
contains.
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68. ● Network layer firewalls generally fall into two sub-
categories.
● 1) Stateful
● 2) Non-Stateful.
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69. ● Stateful firewalls hold some information on the state
of connections as part of their rules.
● Stateless firewalls have packet-filtering capabilities
but cannot make more complex decisions on what
stage communications between hosts have reached.
● Stateless firewalls therefore offer less security.
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71. Q: Explain GPRS.
● General Packet Radio Service.
● GPRS is a packet-switching technology that enables
data transfers through cellular networks.
● It is used for mobile internet, MMS and other data
communications.
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72. ● GPRS is also known as GSM-IP that is a Global-
System Mobile Communications Internet Protocol
as it keeps the users of this system online, allows to
make voice calls, and access internet on-the-go.
● Even Time-Division Multiple Access (TDMA) users
benefit from this system as it provides packet radio
access.
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73. 73

74. ● GPRS also permits the network operators to execute
an Internet Protocol (IP)
based core architecture for integrated voice and data
applications that will continue to be used and expanded
for 3G services.
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75.  Hardware:
● Devices supporting GPRS are divided into three classes:
Class A
● Can be connected to GPRS service and GSM service
(voice, SMS), using both at the same time.
● Such devices are known to be available today.
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76. Class B
● Can be connected to GPRS service and GSM service (voice, SMS), but using
only one or the other at a given time.
● During GSM service (voice call or SMS), GPRS service is suspended, and
then resumed automatically after the GSM service (voice call or SMS) has
concluded.
● Most GPRS mobile devices are Class B.
Class C
● Are connected to either GPRS service or GSM service
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77.  Addressing
● A GPRS connection is established by reference to its
access point name (APN).
● The APN defines the services such as short message
service (SMS), multimedia messaging service (MMS),
and for Internet communication services such as email
and World Wide Web access.
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78.  Protocols supported
● GPRS supports the following protocols:
1.Internet protocol (IP):
● In practice, built-in mobile browsers use IPv4 since
IPv6 was not yet popular.
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79. 2.Point-to-point protocol (PPP).
● In this mode PPP is often not supported by the mobile
phone operator
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80. 3. X.25 connections :
● This is typically used for applications like wireless
payment terminals.
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81.  Advanced Business Applications
1. tracking of taxis and credit card validation for customer payment
2. control over the position of trucks for transportation companies
3. localization of stolen cars
4. support of security and monitoring systems
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82. Q: Explain the Technology
that is used to Connect
Internet.
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83. ● There are mainly three technology is used to connect
with internet.
1) Dial UP
2) ISDN
3) Leased Line
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84. 1) Dial UP :
● Dial-up Internet access is a form of Internet access that
uses the facilities of the public switched telephone
network (PSTN) to establish a connection to an
Internet service provider (ISP) by dialing a telephone
number on a conventional telephone line.
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85. 85

86. ● The user's computer or router uses an attached
modem to encode and decode link layer frames
and control information into and from audio frequency
signals, respectively.
● PSTN consists of telephone lines, fiber optic cables,
microwave transmission links, cellular n/w,
communication satellites.
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87. ● Dial-up requires time to establish a telephone
connection (up to several seconds, depending on the
location) (old nokia phone)
● Slower communication.
● time consuming.
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88. 2)ISDN: - Integrated Services for Digital Network
● ISDN is a set of communication standards for
simultaneous digital transmission of voice, video, data,
and other network services over the traditional
circuits of the public switched telephone network.
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89. ● It was first defined in 1988 in the CCITT red book.
● before to ISDN, the telephone system was viewed as a
way to transport voice, with some special services
available for data.
● The key feature of ISDN is that it integrates voice and
data on the same lines, adding features that were not
available in the classic telephone system.
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90. ● There are several kinds of access interfaces to ISDN
defined as Basic Rate Interface (BRI), Primary Rate
Interface (PRI) Narrowband ISDN (N-ISDN - kbps),
and Broadband ISDN (B-ISDN-mbps).
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91. 91
B-channel (bearer) – Data, voice
D-channel (Delta) – Controlling and signals (ringtones)
BRI – used in
Home, office etc…
2 –B
1 -D
1 channel 24 kbps
2 channel 24*2 =48 kbps
PRI – used in Call
center or MNC
23 –B
1 -D

92. ● ISDN is a circuit-switched telephone network system,
which also provides access to packet switched networks,
designed to allow digital transmission of voice and data
over ordinary telephone copper wires,
resulting in potentially better voice quality than an
analog phone can provide.
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93. 3)Leased Line:
● A leased line is a service contract between a provider
and a customer,
whereby the provider(ISP ) agrees to deliver a
telecommunications line connecting two or more
locations in exchange for a monthly rent (hence the term
lease).
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94. ● If your business has multiple offices, deals
with large amounts of data on a daily
basis or requires a range of different
communications to be supplied together
then a leased could offer you a better
service at a reduced cost.
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95. 95

96. ● Typically, leased lines are used by businesses to
connect geographically distant offices.
● a leased line is always active.
● The fee for the connection is a fixed monthly rate.
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97. Advantages:
● Symmetric: Which means you can upload and
download at the same speed.
● Private and secure : As the connection is just for
your use leased lines are ideal for companies that
handle sensitive client information such those in the
finance and professional services industry.
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98. ● Fast: Leased lines come in range of speeds from
2Mbps up to 10Gbps.
● Unlimited usage: There is no fair usage policy; you
can use as much data as you like.
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100. 100

101. CIA Model.
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102. Q: Give the Principle of Security: CIA Model.
● Confidentiality, integrity and availability, also known
as the CIA.
● This model designed to guide policies for information
security within an organization.
● The model is also sometimes referred to as the AIC
(availability, integrity and confidentiality).
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