Computer networks are becoming more and more advanced and user-friendly day by day due to the fact, that needs and necessities of computer network users are becoming more complicated. But practically there exists some issues and challenges in the data communication and networking field which brings a gap between the advancements in the technology and the users. These issues may be Security risks and threats, social issues, transmission impairments, computer literacy issues, and digital divide or technological availability. This presentation will cover most of these practical issues that exist today.

1. DATA COMMUNICATION &
NETWORKING
ISSUES IN REAL WORLD
H . M . V . T . W B A N D A R A
E P 1 9 9 6
D A T A C O M M U N I C A T I O N & C O M P U T E R N E T W O R K S ( P S T 3 2 2 2 7 )

2. CONTENT
• Introduction
• Data Communication & Networking Issues
– Security Issues
– Transmission Impairments
– Social Issues
– Health Issues
– Environmental Issues

3. Introduction
• What is Data Communication and
Networking?
• History & Evolution
• Current Situation

4. Data Communication & Networking Issues
• Security Issues
• Transmission Impairments
• Social Issues
• Health Issues
• Environmental Issues

5. Security Issues

6. Security Issues
 Denial of Service(Dos) and Distributed Denial of Service Attacks
 Type of attack which affects the availability of resources and services
to legitimate users.
 There are two common types; Flooding attacks and Crash attacks
 Disrupts networks, servers and websites
 Man-in-the-middle Attack
 Type of attack where one party intrudes another party by intercepting
the communication.
 Attackers steal log in credentials, banking information and highly
confidential private information
 Happens mostly with unsecured public networks or hacked home WiFi
connections.

7. Security Issues
 IP Spoofing
 Gaining unauthorized access to machines by manipulating the IP
packets.
 Attacker identifies the host and finds the IP address trusted by the
host and send data packets to the host.
 Involves altering the packet header with fake source IP address, a
checksum and the order value.
 ARP spoofing attacks & DNS server spoofing attacks
 To overcome these types of attacks implementing packet filering, use
of spoofing detection software, use cryptographic network protocols
such as TLS, SSH and HTTPS

8. Security Issues
 Eavesdropping
 Involves illegal interception of private communication which may be a
telephone conversation, instant message, email, fax message or
videoconference to steal information.
 Attackers make use of network monitoring tools on computers which
facilitate data interception and stealing of confidential data
 Port Scan
 It is a method used to gather network information by making use of a
program.
 Attacker tries to find out which ports are free and responding for a
particular IP address and finds vulnerabilities with the port to launch an
attack
 Attackers gain information such as operating system of the target
computer, applications installed and versions of those applications

9. Security Issues
 Social Engineering
 Involves manipulation of people to reveal personal and confidential
information
 Attacker collects information about the target to gain understanding.
 Based on the information collected attacker tries to design and launch
an attack
 Common types of attacks are baiting, phishing, vishing, pretexting,
Scareware and honey trap.
 Masquerade
 Attacker act as a legitimate user who has access to a system and gain
greater priviledges than they are authorized for.
 Launched with stolen login IDs and passwords

10. Security Issues
 Masquerade
 Phishing attacks are a type of variation Masquerade attacks.
 Attackers can setup a similar website of a existing actual website and
users are sent with requests to change the usernames and passwords
with the fake website.
 If the user respond to the website by changing the login credentials,
attacker can easily get access to the user account.

11. Security Issues
 Session Hijacking
 Type of web based attack to networks and systems which is working
based on the concept of sessions.
 Session refers to a certain amount of time period which two
computers or two parties in a computer system or network
communicate with each other.
 Attackers try to intercept active sessions and try to takeover the
session in gaining access to the network or system.
 This type of an attack is not detectable at all, but if the website or the
system is not responding or stops working for no reason, then there
might be a session hijacking.

12. Transmission Impairments

13. Transmission
 Transmission is the process of communication of data and information by the
propagation and processing of signals via a data transferring medium.
 There are two types of transmissions called Analog Transmission and Digital
Transmission.
 Analog transmission involves transmitting of analog signals containing
both analog data such as voice and digital data with binary content.
 Digital transmission signals are composed of binary component and can
be transmitted only to a limited distance.
 Due to this reason only analog signals are used with long distance
transmissions.

14. Transmission Impairments
 These type signals which are being used in transmissions are subjected to
different types of imperfections during the transmission of data.
 That is the signals which are received at the receiver’s end are not the
same signals which are being sent at the sender’s end.
 These imperfections are called as Transmission Impairments
 There are three types of transmission impairments
 Attenuation
 Distortion
 Noise

15. Transmission Impairments
 Attenuation
 It is the decrease in signal strength
with the loss of energy.
 Happens mainly due to the resistance
from the medium and increases with
the increased distance of
transmission.
 Amplifiers are being used to get back
the original signal.

16. Transmission Impairments
 Distortion
 It is the change of shape of signals in
transmission.
 Can be seen generally with composite
signals with different frequencies
 The main cause for distortion is the
propagation of signals through media at
different speeds and when arriving at the
destination, it causes each component to
arrive at different times.
 Then there will observe a different phase
at the receiver’s end than the original
phase.

17. Transmission Impairments
 Noise
 Mixing of unwanted random signals
with original signals is referred as the
Noise in data transmission.
 There exists different types of noises
 Induced Noise – Created from
different sources such as motors
and appliances. These devices act
as sending antenna and
transmission medium acts as the
receiving antenna in creating a
noise effect.

18. Transmission Impairments
 Noise
 Thermal Noise – Created due to movement of electrons in wires
(transmission medium) which generates an additional signal.
 Crosstalk – Generates when two wires which transmit data affects the
other wire creating an unwanted signal generation.
 Impulse Noise – Created due to high energy which results for a very
short period of time, from huge electric sources such as power lines
and lightings.

19. Social Issues

20. Social Issues
 Data Communication and Networking technologies have brought many
advancements, efficiencies, enhancements and reliabilities to the lives of
people.
 At the same time, it has contributed in creating many issues for the society
too.
 That is in the process of communicating with all these digital means and
modes, there could arise many issues and contradictions which will drive
away all the efficiencies and productivity factors of data communication
and networking.

21. Social Issues
 The most common types of Social issues
are
 Digital Divide
 Addiction to Internet/ Social
media
 Creating misunderstandings
and issues between family
members
 Privacy Issues
 Social Isolation
 Accidents

22. Social Issues
 Digital Divide
 It is the gap between those who have
adequate access to computers, internet and
other digital improvements in the technology
and those who do not.
 It is a type of inequality that has aroused in a
new way with technological advancements in
the fields of computing and data
communication and networking.

23. Social Issues
 Digital Divide
 Main factors of Digital Divide are access
to internet and its advancements, quality
of connection, cost for the services,
amount of bandwidth and limits of
connectivity.
 Digital divide may work against
education and learning career of
individuals, knowledge acquisition,
public participation of people in
discussions and decision making
activities etc.

24. Social Issues
 Internet / Social Media Addiction
 Addiction to internet or social media is a
huge issue associated with data
communication and networking.
 It will affect badly for the social lives of
individuals
Ex: Not having enough experience on having
social relationships, getting into fights easily,
loss of morals and social values, not
identifying the value of listening and
understanding ideas, feelings and thoughts
of other people.

25. Social Issues
 Creation of family problems
 With the addiction of internet, there may
arise many issues and problems in family
lives of people.
Ex: Less interaction with each other, no
time discuss with each other, getting
into inappropriate relationships,
divorces and breakage of relationships

26. Social Issues
 Privacy Issues
 Affect to the privacy of individuals is another
social issue associated with data
communication and networking.
 Blackmailing, slandering, insulting, child
abuse, sexual harassments, cyberbullying
are some ways which affects privacy
 Tragic events occur such as suicides,
murders, fights and other terrible events.

27. Social Issues
 Social Isolation
 With people trying to be with computers
and digital devices, all the time they may get
isolated in the society
 People tend to get into long distance and
virtual relationships with social media and
internet while their real life relationships are
damaged.

28. Social Issues
 Accidents
 When people use mobile phones and
other digital devices while driving and
while walking on road accidents can
occur.
 Sometimes not having the enough
attention while driving can result in
accidents.

29. Health Issues
 With modernization of the world with advancement in the technologies related
to data communication and computing, many health issues and risks are
resulted.
 Use of computers for long durations and with the incorrect behaviors of
individuals when using the computers, it might result in physical, mental and
social health risks.
 Most common types of health hazards are
 Back pain, shoulder and arm injuries, injuries in neck area, injuries with
hand and fingers
 Vision and hearing problems
 Headaches and mental stress or depression
 Obesity

30. Health Issues
 Injuries related to back pain

31. Health Issues
 Repetitive Strain Injury

32. Health Issues
 Digital Eye Strain

33. Health Issues
 Obesity

34. Environmental Issues
 Use of computers, digital devices and other equipment for data
communication and networking can cause negative impacts on environment
too.
 The most common problem is the electronic waste or E-waste.
 Landfilling
 Contamination of soil and water with non-biodegradable materials,
heavy metals such as lead, mercury and cadmium and toxic chemical
substances
 Can cause deadly diseases to human beings when consumed those
contaminated water and plant material

35. Environmental Issues
 Land filling due to e-waste

36. Environmental Issues
 Contamination of waterways

37. Environmental Issues
 Other Environmental issues include
 High energy consumption
By 2017 the number of computers in the world is
estimated to be two billion. In every future ten years of
time this will be doubled.
 Degradation of natural resources
Use of fossil fuels and other energy sources to in energy
generation

38. THANK YOU!