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Instructor & Todd Lammle. Sybex CCNA 640-802 Chapter 14: Cisco Wireless Technologies. Chapter 14 Objectives. The CCNA Topics Covered in this chapter include: What is a WLAN? IEEE Standards CSMA/CD ISM channels UNII Band BSS/ESS Wireless Security. 2. Wireless LAN’s.
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Instructor & Todd Lammle Sybex CCNA 640-802 Chapter 14: Cisco Wireless Technologies
Chapter 14 Objectives The CCNA Topics Covered in this chapter include: • What is a WLAN? • IEEE Standards • CSMA/CD • ISM channels • UNII Band • BSS/ESS • Wireless Security 2
Wireless LAN’s • Transmitting a signal using the typical 802.11 specifications works a lot like it does with a basic Ethernet hub: They’re both two-way forms of communication, and they both use the same frequency to both transmit and receive, often referred to as half-duplex. • Wireless LANs (WLANs) use radio frequencies (RFs) that are radiated into the air from an antenna that creates radio waves. 3
802.11 Standards Here are the most popular standards in use today: • 802.11b: 2.4Ghz, maximum bandwidth of 11Mbps • 802.1g: 2.4Ghz, up to 54Mbps • 802.11a: 5Ghz, up to 54Mbps • 802.11n: Higher throughput improvements using MIMO (multiple input, multiple output antennas) 6
2.4GHz/5GHz (802.11n) The following three vital items are combined in 802.11n to enhance performance: • At the Physical layer, the way a signal is sent is changed, enabling reflections and interferences to become an advantage instead of a source of degradation. • Two 20Mhz-wide channels are combined to increase throughput. • At the MAC layer, a different way of managing packet transmission is used. 11
Ad Hoc mode 13
Wireless Security • Open Access • SSIDs, WEP, and MAC Address Authentication • Wi-Fi Protected Access (WPA) • WPA or WPA2 Pre-Shared Key • WPA or WPA2 Enterprise • 802.11i • Encryption Methods • Temporal Key Integrity Protocol (TKIP) • AES 16
Summary • Summary • Open your books and go through all the written labs and the review questions. • Review the answers in class. 19