Presentation is loading. Please wait.

Presentation is loading. Please wait.


Similar presentations

Presentation on theme: "BZUPAGES.COM BSIT 07-11. BZUPAGES.COM BSIT 07-11 ON."— Presentation transcript:



3 BZUPAGES.COM  D anis H ussaino7-o9  T aha Khano7-o6  I mran Khano7-37  F arrukh Alio7-43 BSIT 07-11

4 BZUPAGES.COM Introduction Wi-Fi Technologies Wi-Fi Architecture & Types Wi-Fi Network Elements Types of Hardware How a Wi-Fi Network Works Applications of Wi-Fi Wi-Fi Security Advantages/ Disadvantages of Wi-Fi BSIT 07-11

5 BZUPAGES.COM Wireless Technology is an alternative to Wired Technology, which is commonly used, for connecting devices in wireless mode. Wi-Fi (Wireless Fidelity) is a generic term that refers to the IEEE 802.11 communications standard for Wireless Local Area Networks (WLANs). Wi-Fi Network connect computers to each other, to the internet and to the wired network. BSIT 07-11

6 BZUPAGES.COM BSIT 07-11 Wi-Fi or 802.11b/g is the wireless standard used for local area networks operating at 2.4GHz. Virtually every new laptop and mobile being sold today comes already equipped with a compatible wireless WiFi adapter. The WiFi dial-up wireless router is compatible with either 802.11b or 802.11g adapters and allows local network data transfers at speeds of up to 11Mbps (megabits per second). All Intel Centrino laptops as well as adapters marked 802.11a/g are compatible.

7 BZUPAGES.COM Wi-Fi Networks use Radio Technologies to transmit & receive data at high speed: IEEE 802.11b IEEE 802.11a IEEE 802.11g BSIT 07-11

8 BZUPAGES.COM Appear in late 1999 Operates at 2.4GHz radio spectrum 11 Mbps (theoretical speed) - within 30 m Range 4-6 Mbps (actual speed) 100 -150 feet range Most popular, Least Expensive Interference from mobile phones and Bluetooth devices which can reduce the transmission speed. BSIT 07-11

9 BZUPAGES.COM Introduced in 2001 Operates at 5 GHz (less popular) 54 Mbps (theoretical speed) 15-20 Mbps (Actual speed) 50-75 feet range More expensive Not compatible with 802.11b BSIT 07-11

10 BZUPAGES.COM Introduced in 2003 Combine the feature of both standards (a,b) 100-150 feet range 54 Mbps Speed 2.4 GHz radio frequencies Compatible with ‘b’ BSIT 07-11

11 BZUPAGES.COM Access Point (AP) - The AP is a wireless LAN “base station” that can connect one or many wireless devices simultaneously to the Internet. Wi-Fi cards - They accept the wireless signal and relay information.They can be internal and external.(e.g PCMCIA Card for Laptop and PCI Card for Desktop PC) Safeguards - Firewalls and anti-virus software protect networks from uninvited users and keep information secure. BSIT 07-11

12 BZUPAGES.COM Antennas come in all shapes and styles: OOmni-directional: VVertical Whip CCeiling mount DDirectional: YYagi (“Pringles can”) WWall mounted panel PParabolic dish BSIT 07-11

13 BZUPAGES.COM Wi-Fi Architecture & Types BSIT 07-11

14 BZUPAGES.COM We can manage the WLAN (wireless local area network) with several types: AAd-Hoc Mode MMesh Mode IInfrastructure Mode BSIT 07-11

15 BZUPAGES.COM  Peer-to-peer setup where clients can connect to each other directly. Generally not used for business networks. BSIT 07-11

16 BZUPAGES.COM  Mobile stations communicate to each other directly.  It’s set up for a special purpose and for a short period of time.  For example, the participants of a meeting in a conference room may create an ad hoc network at the beginning of the meeting and dissolve it when the meeting ends. BSIT 07-11

17 BZUPAGES.COM  Every client in the network also acts as an access or relay point, creating a “self- healing” and (in theory) infinitely extensible network.  Not yet in widespread use, unlikely to be in homes. BSIT 07-11

18 BZUPAGES.COM BSIT 07-11 There is an Access Point (AP), which becomes the hub of a “star topology.” which becomes the hub of a “star topology.”

19 BZUPAGES.COM  There is an Access Point (AP), which becomes the hub of a “star topology.”  Any communication has to go through AP. If a Mobile Station (MS), like a computer, a PDA, or a phone, wants to communicate with another MS, it needs to send the information to AP first, then AP sends it to the destination MS  Multiple APs can be connected together and handle a large number of clients.  Used by the majority of WLANs in homes and businesses. BSIT 07-11



22 BZUPAGES.COM Basic concept is same as Walkie talkies. A Wi-Fi network is created by installing an access point to an internet connection. An access point acts as a base station. BSIT 07-11

23 BZUPAGES.COM BSIT 07-11 A single access point can support up to 30 users and can function within a range of 100 – 150 feet indoors and up to 300 feet outdoors.A single access point can support up to 30 users and can function within a range of 100 – 150 feet indoors and up to 300 feet outdoors. Many access points can be connected to each other via Ethernet cables to create a single large network. Many access points can be connected to each other via Ethernet cables to create a single large network.

24 BZUPAGES.COM Wireless Security BSIT 07-11

25 BZUPAGES.COM Wireless technology doesn’t remove any old security issues, but introduces new ones Eavesdropping Man-in-the-middle attacks Denial of Service BSIT 07-11

26 BZUPAGES.COM Easy to perform, almost impossible to detect By default, everything is transmitted in clear text Usernames, passwords, content... No security offered by the transmission medium Different tools available on the internet Network sniffers, protocol analysers... Password collectors With the right equipment, it’s possible to eavesdrop traffic from few kilometers away BSIT 07-11

27 BZUPAGES.COM 1. Attacker spoofes a disassociate message from the victim 2. The victim starts to look for a new access point, and the attacker advertises his own AP on a different channel, using the real AP’s MAC address 3. The attacker connects to the real AP using victim’s MAC address BSIT 07-11

28 BZUPAGES.COM Attack on transmission frequecy used Frequency jamming Not very technical, but works Attack on MAC layer Spoofed deauthentication / disassociation messages can target one specific user Attacks on higher layer protocol (TCP/IP protocol) SYN Flooding BSIT 07-11


30 BZUPAGES.COM The requirements for Wi-Fi network security can be broken down into two primary components: Authentication  User Authentication  Server Authentication Privacy BSIT 07-11

31 BZUPAGES.COM Keeping unauthorized users off the network User Authentication Authentication Server is used Username and password Risk: Data (username & password) send before secure channel established Prone to passive eavesdropping by attacker Solution Establishing a encrypted channel before sending username and password BSIT 07-11

32 BZUPAGES.COM Server Authentication Digital Certificate is used Validation of digital certificate occurs automatically within client software BSIT 07-11

33 BZUPAGES.COM Home Small Businesses Large Corporations & Campuses Health Care Wireless ISP (WISP) Travellers BSIT 07-11

34 BZUPAGES.COM Mobility Ease of Installation Flexibility Cost Reliability Security Use unlicensed part of the radio spectrum Roaming Speed BSIT 07-11

35 BZUPAGES.COM Interference Degradation in performance High power consumption Limited range BSIT 07-11

36 BZUPAGES.COM AnY Qu3sTioN?? BSIT 07-11

Download ppt "BZUPAGES.COM BSIT 07-11. BZUPAGES.COM BSIT 07-11 ON."

Similar presentations

Ads by Google