Upload
patia
View
55
Download
0
Embed Size (px)
DESCRIPTION
Chapter 5 LANs and WLANs. Wireless Basics. A wireless network transports data from one device to another without cables or wires Slower than wired networks Susceptible to interference Security concerns Signals in air are easily intercepted. RF Radio Frequency. RF signals - PowerPoint PPT Presentation
Citation preview
Computer Concepts 2012
Chapter 5LANs and WLANs
5
Chapter 5: LANs and WLANs 2
Wireless Basics A wireless network transports data from one device to
another without cables or wires Slower than wired networks
– Susceptible to interference Security concerns
– Signals in air are easily intercepted
5 RF Radio Frequency
Chapter 5: LANs and WLANs 3
– RF signals– radio frequency or radio waves
• Transceiver • sends and receives
5
Chapter 5: LANs and WLANs 4
• Microwaves • line-of-sight transmissions• corporate MANs]
Microwave Transmission
5
Chapter 5: LANs and WLANs 5
• Infrared light• Clear line-of-sight• Short distances• PAN personal network
Infrared Light
5
Chapter 5: LANs and WLANs 6
Bluetooth Short-range, wireless network technology
– designed to make its own connections between electronic devices• without wires, cables, or direct action from user
5
Chapter 5: LANs and WLANs 7
Wi-Fi Equipment
5
Chapter 5: LANs and WLANs 8
Wi-Fi Equipment If your computer is not pre-equipped with wireless circuitry,
you can purchase and install a Wi-Fi adapter
5 Wi-Fi Setup
Chapter 5: LANs and WLANs 9
5
Chapter 5: LANs and WLANs 10
Wi-Fi Setup Change Password upon logging onto to wireless router
– Logon via browser with router IP address
Enter an SSID for the network– Name your network
• This differentiates it from nearby networks
Choose WEP, WPA, or PSK – This activates encryption protection between nodes
Set up the wireless workstations Connect an Internet access device
5 Wi-Fi Security Router Interface
Chapter 5: LANs and WLANs 11
5
Chapter 5: LANs and WLANs 12
Wi-Fi Security Wireless encryption scrambles data transmitted between
wireless devices and then unscrambles the data only on devices that have a valid encryption key– WEP (Wired Equivalent Privacy)– WPA (Wi-Fi Protected Access)– WPA2– PSK
Activate encryption by using a wireless network key
5
Chapter 5: LANs and WLANs 13
Encryption Encryption transforms a message so that its contents are
hidden from unauthorized readers– Plaintext has not yet been encrypted– An encrypted message is referred to as ciphertext
Decryption is the opposite of encryption– Cryptographic algorithm– Cryptographic key
5
Chapter 5: LANs and WLANs 14
Encryption Public key encryption (PKE) eliminates key-distribution
problem, by using one key to encrypt a message and another key to decrypt the message
5 SECTION D
Chapter 5: LANs and WLANs 15
Using LANs LAN Advantages and Challenges Sharing Files Sharing Printers Network Troubleshooting
5
Chapter 5: LANs and WLANs 16
LAN Advantages LANs enable people to work together
Sharing networked software can reduce costs
Sharing data on a LAN can increase productivity
Sharing networked hardware can reduce costs
Sharing networked hardware can provide access to a wide range of services and specialized peripheral devices
5
Chapter 5: LANs and WLANs 17
LAN Challenges Resources become unavailable when network malfunctions
Networks may be vulnerable to unauthorized access– More vulnerable than standalone computers
• Wireless networks can be tapped from any computers within range of the wireless signal
Networked computers are susceptible to an increasing number of worms, Trojan horses, and blended threats
5
Chapter 5: LANs and WLANs 18
Sharing Printers Three setups allow for printer sharing:
– Set up printer sharing using a workstation printer– Set up printer sharing using a print server– Install printer with built-in networking
Computer Concepts 2012
Chapter 5 Complete