1. System failure &
wireless security

2. System Failure
- Is computer security risk
-Prolonged malfunction of
a computer

3. Effects
Loss of
hardware, software, data and
information

4. Reason
• User error
• Water / fluid
• Dirt / dust
• Heat
• Cold

5. • Aging hardware
• Natural disaster
• Random events
• Errors in computer programs
• Electrical power variation
And other reAsons……

6. Electrical Disturbance
• Noise
• Undervoltage
• Overvoltage / Power
surge
• Momentary Interruption

7. Noise

8. Undervoltage
• Brownout / Sag
• Blackout

9. Overvoltage / Power Surge
• Surge
• Spike

10. Momentary Interruption

11. Safeguards against
System Failure

12. Surge protector

13. Function of surge protector
• Protect electric component from
‘’surgers’’
• Protect the computer and other
equipment from large overvoltages and
undervoltages.

14. What actions we can do to
Protect our
surge protectors???

15. 1.Replacing a surge
protector every two
to three years.
2.More expensive,
the more protection
of the protectors
offers.
metal oxide varistor (MOV)

16. How we know the surge
protector we purchase is the
best one???
Safety specification-Underwritters
Laboratories(UL)1449 standard.
The Joule rating of the surge protectors.
(higher joule rating ,the better protection)
-review the manufacture’s guarantee

17. UPS(Uninterrupted Power
Supply)
• UPS = Surge protection circuits + 1 or more
batteries
• UPS provides power during loss of power
• You connect a UPS between your computer
and power source
COMPUTER – UPS – POWER SOURCE

18. Types of UPS
Don’t worry there are only two of them
Standby/Offline Online
• Always runs off battery
• Switches to battery power
when power offline . • Provides continuous
protection
• Amount of time to
continue using your • More expensive
computer depends on
electric requirement of
the computer and size of
the batteries.
• Less expensive

19. Duplicate Components/ Fault-tolerant
Computer
Fault-tolerant computer has duplicate computers
so that it can continue to operate when one of its
main components fail
Some Companies have fault-tolerant computers
working simultaneously so that their computers
are always running.
For example,airline tickets reservation,automated
teller machine.

21.  Home user set up wireless home network.
 Mobile user access wireless networks in
hot sport at airport, hotels, shopping mall
and so on.
 Although wireless access provides many
conveniences, it also posses additional
security risk.

22. WHAT IS WIRELESS SECURITY?
 It is the prevention of unauthorized access
to computer using wireless networks.

23. TYPES OF WIRELESS SECURITY
a) WEP (Wireless Equivalent Privacy)
• Is one of the least secure form of security
b) WPA (Wi-Fi Protected Access)
• Is a quick alternative to improve security over
WEP

24. TIPS FOR WIRELESS
HOME NETWORK
SECURITY

25. 1.CHANGE DEFAULT
ADMINISTRATOR
PASSWORD
•Thepassword provided are simple and very well-
known to hackers on Internet

26. 2.TURN ON WPA ENCRYPTION
 Encryption technology scrambles
messages sent over wireless network , so
they cannot easily read by humans.

27. 3.CHANGE THE DEFAULT SSID
 Change your network’s SSID to something
unique .

28. 4.ENABLE MAC ADDRESS
FILTERING
 With MAC address filtering, you specify
which computers can access your
network.

29. 5. DO NOT AUTO-
CONNECT TO OPEN WI-FI
NETWORKS

30. 6. ASSIGN STATIC IP
ADDRESS TO DEVICES
 DHCP (Dynamic Host Configuration
Protocol)technology
 Network attackers can easily obtain valid IP
addresses from your network's DHCP pool.
 Turn off DHCP on the router or access point, set a
fixed IP address range instead, then configure each
connected device to match.
 Use a private IP address range (like 10.0.0.x)

31. 7. ENABLE FIREWALLS ON
EACH COMPUTER AND THE
ROUTER

32. 8. POSITION THE
ROUTER OR ACCESS
POINT SAFELY
 Wi-Fi signals leakage - easier for others to detect
and exploit.
 Try to position the access point or router near the
centre of the home rather than near windows -
minimize leakage.

33. 9. TURN OFF THE
NETWORK DURING
EXTENDED PERIOD OF
NON-USE
 If you own a wireless router but are only using it
wired (Ethernet) connections, you can turn off Wi-
Fi on a broadband router without powering down
the entire network.