1. Anatomy of an 802.11 Wi-Fi Enterprise Wireless LAN Chris De Herrera Pacific Crest Bank Chief Information Officer Webmaster, Tablet PC Talk, CEWindows.NET

2. Overview Glossary of the terms used in Wi-Fi Wi-FI Characteristics Hardware Requirements Ad Hoc vs. Infrastructure Positioning APs Security Demonstration Competing Wireless LAN Options Questions and Answers

3. Glossary 802.11, Wireless Ethernet, Wi-Fi - A wireless local area network protocol which allows high speed access to network resources. It operates at 11, 5.5, 2 and 1 megabits per second depending on distance. It uses the 2.4 ghz spectrum using direct sequence spectrum (DSS).. WECA is the industry consortium which works with vendors on interoperability. WECA ESSID – Extended Service Set Identifier - Specifies which 802.11b network you are joining. Some systems allow you to specify ANY SSID as an option so you can join any network. WEP - Wired Equivalent Privacy - the standard for encrypting data over an 802.11b wireless network. This 40 or 128 bit encryption has been shown to be insecure. So the current recommendation is to use a VPN, limit MAC Address, or 802.1x to secure corporate data. Additional terms are defined at http://www.cewindows.net/glossary.htm

4. Wi-Fi Characteristics Supports 1,2,5.5 and 11mb/s speeds Provides coverage of up to 500 feet indoors and 1500 feet outside Up to 100mW of transmit power Limited to 3 simultaneous channels of communication – This affects the coverage design for a given area to prevent overlapping channels Half Duplex – Only one device can transmit at a time Supports roaming between access points if they are on the same subnet and use the same SSID.

5. Hardware Requirements PC Card or Compact Flash Card – see http://www.cewindows.net/peripherals.htm (includes antenna sensitivity, power output, etc) http://www.cewindows.net/peripherals.htm Access Point – Really just a bridge between Wi-Fi and Ethernet. Local Area Network Ethernet Switch

6. Ad Hoc vs. Infrastructure Ad Hoc is the term used to explain when a user is connecting to another 802.11b device directly without an access point. The user must decide what IP address and subnet to communicate. Infrastructure is the term used to explain when a user is connecting to the wireless LAN using an Access Point. The Access Point or another network device can provide services like DHCP and NAT.

7. Positioning APs Get a floorplan to indicate where to place APs to cover the area. Test for interference – 2.4 gHz equipment, Microwaves, Other Metal Objects Test coverage

8. Security You need to secure your data that is sent via wireless. Using WEP is not enough to prevent unauthorized access to your Wi-Fi LAN. WEP is easy to crack. Limiting MAC addresses does not encrypt your data. Using 802.1x limits who can access your Wi-Fi LAN but does not encrypt your data Using a VPN encrypts your data and restricts who is authorized to access your Wi-Fi LAN Dont forget physical security of APs. Future – 802.11i

9. Demonstration Basic configuration of a Linksys WAP11 Access Point

10. Competing Wireless LAN Options 802.11a – Current high speed standard – 54 mb/s. Uses 5 gHz. About ½ the coverage of Wi-Fi. 802.11g – Up and coming standard that has not been ratified. Backward compatible with Wi-Fi. Operates at 54 mb/s. Uses 2.4 gHz. About the same coverage as Wi-Fi.

11. Anatomy of an 802.11 Wi-Fi Enterprise Wireless LAN Questions and Answers Chris De Herrera Pacific Crest Bank Chief Information Officer Webmaster, Tablet PC Talk, CEWindows.NET

12. Anatomy of an 802.11 Wi-Fi Enterprise Wireless LAN Chris De Herrera Pacific Crest Bank Chief Information Officer Webmaster, Tablet PC Talk, CEWindows.NET