1 / 21

Wireless State of the LAN

Explore the importance of wireless LAN, its security, administration, selection, and deployment issues. Get tips and tricks for successful wireless implementation.

robertldavis
Download Presentation

Wireless State of the LAN

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Wireless State of the LAN EDUTEX 2001 San Antonio Doug Jackson Director, Technology Customer Services University of Texas at Dallas

  2. Introduction • What is “Wireless”? • Why is Wireless Important? • WLAN Security & Administration • WLAN Selection & Deployment Issues • Tips’N’Tricks • URLs

  3. What is “Wireless”?

  4. What is “Wireless”? • Cellular? Microwave? Infrared? • Wireless LAN is Spread Spectrum Radio • 3 Basic Topologies- • Infrared (IRDA) • Frequency Hopping (FHSS) and • Direct Sequence (DSSS) • FH greater density, shorter range, slower speed, less prone to interference (79 channels) • DS lower density, greater range, higher speed, more susceptible to interference (15 channels)

  5. What is “Wireless”? • Standards (key to interoperability) • IEEE 802.11 • 802.11b- DSSS @11Mbps 2.4GHz • 802.11a- DSSS @54Mbps 5GHz • 802.11g- DSSS @22Mbps 2.4GHz • 802.11e- DSSS @22Mbps w/QoS • 802.11 is “shared ethernet” • 802.11 is “collision avoidance” (CSMA/CA instead of CSMA/CD)

  6. Why is “Wireless” Important? • Perfect for “retrofit networking” • No pulling cables • No “building renovation” • Connections to spaces wires can’t • Excellent space optimization • No “computer rooms” • Extend class/meeting rooms • Simple installs, reduced labor costs, lower cost of ownership • Fosters more collaborative activities

  7. Why is “Wireless” Important? • Great for travel • Airports (DFW, Austin, etc.) • Hotels • Provides more flexibility • At home (couch potatoes!) • Cafeterias, common areas • Ubiquitous, Anytime, Anywhere network connectivity!

  8. Why is “Wireless” Important? • UT Dallas Wireless Projects for 1999-2000: • Library laptops for checkout by students • Largest Classroom building • Conference Center • Ad Hoc networking “kits” • WLAN Projects for 2001 • Student apartments • Student Union • Selected Common Areas

  9. WLAN Security & Administration Issues • Only as secure as the wired portion of the network • WEP uses either 40 (default) or 64 bit RC4 encryption • May use VPN for added security • Most vulnerable point is between laptops within same cell • Load balancing, roaming essentially managed by AP’s

  10. WLAN Selection & Deployment Issues • Leaders include: • Avaya (Lucent) • Symbol (Intel) • Cisco (Aironet) • Proxim, 3Com, Breezecom, etc. • Vendors embracing WLANs: • Apple (for over a year) • IBM • Dell • (Everybody is doing it!)

  11. WLAN Selection & Deployment Issues • Utilize 802.11b standards (or 802.11a) • Consider situational factors • Range- 150ft per cell • Available channels- 3 to 5 • Cell overlap (and failovers) • Potential Interference- microwaves, cellphones (2.4GHz devices) • “Dead” zones- metal, concrete w/rebar, reflective surfaces

  12. WLAN Selection & Deployment Issues • Top 3 Deployment Concerns • RF Survey • RF Survey • RF Survey • Use of appropriate antennas • Airspace ownership (policy issue?) • Significance of roaming capability • Power over Cat5 media

  13. WLAN Selection & Deployment Issues • Plan for 20-30 users per AP • Locate AP’s considering cell overlap • Plan for 3D, not 2D • Do RF survey with bodies in place • Plan for electrical- both for AP and for laptop battery rechargers • Determine security needs and effective alternatives

  14. Tips N Tricks #1 • Always do a site survey • Vendors think horizontally and not vertically (or “spherically”) • Vendors want success stories • If it’s not standard, avoid it! • Co-located access points should be at least 5 channels apart (thus a max of 3) - practice shows 4 apart works with little or no signal degradation

  15. Tips N Tricks #2 • Wireless card will shorten battery life by at least 50% • If it’s the first “big” wireless project, consider a consultant! • Wireless doesn’t have to be “sold”, but you have to test it, announce it, demo it, & have gear readily available • Wireless infrastructure can be grown incrementally or purchased “turn key”

  16. Tips N Tricks #3 • 11Mb fails to 5.5Mb fails to 2Mb fails to 1 Mb fails to 0 • Who owns the airspace? List of “banned” devices? • Interference: Bluetooth, other AP’s, 2.4GHz phones, microwave • Costs: AP <$650, NIC cards <$150 • Use only 1 segment, if possible, for effective roaming

  17. Tips N Tricks #4 • Perform RF site survey with bodies in place • Printing considerations still there, maybe worse! • Don’t put antenna too high! • Wireless is principally a retrofit technology • Plan for 15-25 users per AP with 802.11b

  18. Tips N Tricks #5 • 802.11a (54Mbps, 5GHz range) (less potential interference) • Battery life goes down as speeds go up • Power over CAT5 wiring available, no extension cords! • Tradeoffs: range vs. bandwidth vs. cost • Authentication issues? VPN for “best” security?

  19. URLs • Avaya.com (Lucent) • Symbol.com (Intel) • Cisco.com (Aironet) • Proxim.com • Mobilestar.com • www.wlana.com/intro/introduction/index.html • www.bluetooth.com • http://www.apple.com/airport/ • http://www.dell.com/us/en/hied/topics/vectors_1999-wireless.htm

  20. URLs • Higher Ed Success Stories • Carnegie Mellon http://www.cmu.edu/computing/wireless/ • Buena Vista University http://ebvyou.bvu.edu/ • UT Austin (ACES) http://www.aces.utexas.edu/ • Marquette University Engineering http://www.eng.mu.edu/wireless/ • Andrews University http://www.andrews.edu/wireless/wirelesszone/ • Valdosta State http://www.valdosta.edu/wireless/ • To name a few…

  21. URLs • For copies of this presentation: • Email: Jackson@utdallas.edu • For more information: (White papers & more URL’s) www.utdallas.edu/ir/wlans/

More Related