WIRELESS Networks - PowerPoint PPT Presentation

1 / 27
About This Presentation
Title:

WIRELESS Networks

Description:

WIRELESS. Networks. Wireless networks. Comfortable. Informality. No cables. Leaking information ... Connect with cable to the wired LAN. Masked area: cell ... – PowerPoint PPT presentation

Number of Views:31
Avg rating:3.0/5.0
Slides: 28
Provided by: komrom
Category:

less

Transcript and Presenter's Notes

Title: WIRELESS Networks


1
WIRELESSNetworks
2
Wireless networks
  • Comfortable
  • Informality
  • No cables
  • Leaking information
  • SSID Broadcasting

3
WLAN topologies
  • Ad-Hoc
  • Infrastructured method topology

4
  • Ad-Hoc

5
Ad-Hoc
  • Casual network
  • All computers are clients and hosts too
  • Low transfer speed
  • Bad security
  • Compatibility problems

6
Infrastructured method topology
  • Prevention of compatibility problems
  • Create acces points
  • Connect with cable to the wired LAN
  • Masked area cell

7
  • Infrastructured method topology

8
WLAN tools
  • Wireless network card
  • Simple wireless card (Desktop computers)
  • PCMCIA card (Laptops)
  • External USB wireless key
  • Integrated card
  • Acces point

9
Technological properties
  • The electro-magnetic indications
  • Extend to straight
  • Longer distance -gt lower intensity
  • Reflections interference

10
Modulation procedures
  • AM Amplitude modulated
  • FM Frequency modulated
  • PM Period Modulated

11
Modulation procedures
12
Wireless Ethernet technologies
  • IEEE 802.11
  • IEEE 802.11 a
  • IEEE 802.11 b
  • IEEE 802.11 g

13
(No Transcript)
14
IEEE 802.11
  • 2,4 GHz frequency range
  • 1-2 Mbit/s transfer-rate
  • DSSS - Direct Sequence Spread Spectrum
  • FHSS - Frequency Hopping Spread Spectrum

15
IEEE 802.11 b
  • 2,4 GHz frequency range
  • 1 2 5,5 11
  • HR-DSSS Wi-FiTM
  • Compatible with older technologies

Mbit/s transfer-rate
16
IEEE 802.11 a
  • 5 GHz frequency range
  • 54 Mbit/s transfer-rate
  • With data duplication 108 Mbit/s
  • 52 used frequency
  • Not fully compatible with other technologies

17
IEEE 802.11 g
  • 2,4 Ghz ISM band
  • 54-108 Mbit/s transfer-rate
  • Modulation procedure OFDM
  • Fully compatible with older technologies
  • This is the most used technology

18
WLAN security
  • Disable the SSID Broadcasting
  • Network identifier (MAC) filter
  • Use data encryption
  • Opened WLAN

19
(No Transcript)
20
War Spamming
  • Less defended Acces Points
  • Mailing system
  • Unbidden mails Spam
  • Hard to protect

21
Data Encryption Standards
  • WEP Wired Equivalent Privacy
  • WPA Wi-Fi Protected Access
  • IEEE 802.11Tgi - WPA2

22
WEP
  • RC4 procedure
  • 40 or 104 bit keys
  • Static keys
  • Key changer protokolls
  • 24 bit Initialize Vectors - IV

23
WPA
  • Fix WEPs disadventages
  • 48 bit IV
  • TKIP Temporal Key Integrity Protocol
  • AES - Advanced Encryption Standard
  • 8 bit MIC Message Integrity Code
  • WPA and WEP can used together

24
IEEE 802.11Tgi
  • IEEE Taskgroup i
  • AES Advanced Encryption Standard
  • 128-256 bit keys
  • The most up-to-date technology
  • Compatible with WPA protokolls

25
War Driving
  • Car
  • Antenna
  • Laptop
  • Route
  • Freetime

26
Statistics
  • From 100 WLAN
  • 55 opened ( 5 original SSID )
  • 25 WEP/WPA
  • 20 WPA2
  • Un-official datas

27
End
Write a Comment
User Comments (0)
About PowerShow.com