Thornbury U3A Computer GroupThornbury U3A Computer Group

Wireless NetworkingWireless Networking(Part 1)(Part 1)

September 2006 Mike Farquhar September 2006 Mike Farquhar

Wireless Networking

•Define:

Communicating between 2 or more computers without wires

•Networking – –wireless or wires–Why do we want or need to do it?

Why do we network computers ?

To share resources:1. Printers2. A “server” to keep all your data in one place so that

it is accessible anywhere (Microsoft Windows XP Media Center Edition 2005)

3. Internet Connection – especially a Broadband Internet Connection

– Broadband in this area at least comes in 2 main flavours– Cable (from Telewest – now part of NTL)– ADSL via your phone line (Asymmetric Digital Subscriber

Line)– Technically Cable is a better solution (separate circuit – no

fiddly filtering)

WANs and LANs

WANs and LANs

USB AdapterInternal PCI card PCMCIA Card

Router Modem

ADSL Router

Cable !!!

USB Adapter PCI card PCMCIA card Compact Flash

SatelliteNavigationSystem

(based on the Pocket PC)

4-port ADSL Wireless RoutersOlder style Latest style

Configuring Wireless networks

• Infrastructure mode or Peer to Peer

• Wireless network name or SSID

• Channel. In Infrastructure mode all devices use the same channel.

Configuring Wireless Security - 1

• WPA – WiFi Protected Access– WPA PSK– WPA RADIUS

• WEP – Wired Equivalent Privacy– 64 bits– 128 bits (stronger security) This requires a 26

hex digit key, normally generated by a passphrase)

WEP is an older system but, at 128bit, is perfectly adequate for normal households.

Configuring Wireless Security - 2

• Each network card (of any sort) has an unique 12 digit (hexadecimal) address.

• This is a world-wide standard and is called the MAC address (Media Access Control)

• You can program your router to allow or restrict access based upon individual MAC addresses