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Wireless / Mobile Networking Update

Chad Burnham, Shannon Valerio

& Byron Early

University Technology Services

April – 2002 – CHECO Spring Conference

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DU’s Laptop Learning Model: Undergraduate Laptop program in place since

Fall ’99 Students learn to utilize technology WHILE

learning educational content ‘01-’02: All undergrad & MBA students required

to have laptops with wired 10/100 Ethernet card. Laptops showing up with 802.11b cards built in.

Students are asking about where & how on campus. ~5000+ student laptops on & off DU network ~150-200 faculty use laptops via departments,

grants (some self funding)

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The Ricks Center DU’s private K-8 school First wireless system was proprietary infrared technology: Summer

2000 NOT VERY SUCCESSFUL.

Recently moved to: 4 x 802.11b Access Points

72 Laptops Provided by Center Next Year:

Recommending 7-8th Grade bring own Group & individual research flexibility Web Publishing application E-mail Lower bandwidth type applications

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Rick Center: Continued

Purchased mobile Dell Cart to secure units

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Penrose Library

10 802.11b Access Points Installed Redefining the library…. Provides for wireless access for students, staff and

faculty in library VPN must be used – Summer ‘02

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Laptop Technology in DU’s Curriculum

Wireless network access is an overlay network service designed to provide physical flexibility in: Open Areas – “Hot Spots” (inside & outside) Wired Classrooms

Center for Teaching and Learning (CTL) Academic grants used as incentives for divisions to

‘convert’ to digital media. DU’s Blackboard On-line Class Implementation

Homework, Syllabus, Class Notes, PowerPoint Slides, quizzes.

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Wireless Technology Concerns @ DU Bandwidth limitations:

Slower performance than wired 10/100 mpbs switching Privacy & Security

Encryption & Authentication Network Snooping – Separate VLANs for Wireless

networks (not ‘on-top’ of existing) Technical Support:

Card Installs: its all about the “DRIVERS” VPN Software: Installation/configuration User password issues (Single Sign-on)

AD / LDAP / Kerberos?

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Wireless Technology Concerns @ DU - Continued

Evolving/changing wireless technologies & PC operating systems: Incompatibilities with installed base Upgrade costs

Rouge Access Points – Dept Installed Security Issues – Network Access Performance Issues (Duplex) CDW ad: “I can do wireless”, “what is wireless”? Top Level policy needed

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Wireless Network Benefits for DU

Convenience Places you cannot wire

Historical buildings Access problems Cannot get fiber uplink to

Flexibility physical group learning models New type of “smart-classroom”

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So now you want to build a wireless network?

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“The RF Site Survey”

Can use outside firm or do in-house ~$100 per/hr per/person DU tried 2 different firms – limited use now

Dictates # of APs and placement of APs Direct driver of total cost of ownership

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Site Survey Recommendations

Use 3 people to do the surveys: 1 person @ proposed base area with AP & various

antenna types Changing Antennas type/position/location Documenting results

2 people on wireless laptops (w/802.11x radio) & handheld radios

Documenting SNR (in software) – to be overlaid on to maps/floor plans.

Do not do survey from blue-prints New buildings: with furniture and people present

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Antenna Placement

Do not place antennas near metal objects Wave degradation issues Railings, I-Beams, Lath, Etc.

Separation important Think 3D (patterns vary by antenna type) Away from wall if possible Keep coax / LMR waveguide to minimum length

Move the data cable & AP before making coax longer Inside buildings: choose antenna patterns that

confine RF signal (unless desired)

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Wave Guide / LMR COAX Cabling from Antenna to Access Point LMR 200/400/600/800, etc. = Size & Loss

Properties LMR have very low signal loss properties Times Microwave is industry leader in cable, prep tools,

and connectors. Others in market space under other names

Newer Balun (75 <-> 50 Ohm) & Amplifier combo units available to deliver over cheaper RG-6 Coax

Every Db matters in link budget!

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Antenna Variables to look for:

Beam Coverage: Horizontal & Vertical (in degrees)

Antenna gain: rating in Dbi. Size/Shape Aesthetics

Remember: must have line of sight! Cost 2.4 GHz rated (802.11b)

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RF: Its all in the Antenna….

A. Parabolic Grid AntennasB. Radome-Enclosed Yagi AntennasC. Omni Directional AntennasD. Patch Antennas (Bow-Tie)E. Planar Array Panel AntennasF. Heavy-Duty Panel AntennasG. Mobile AntennasH. Indoor Ceiling-Mount AntennasI. "Rubber Duck" Antennas

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A. Parabolic Grid Antennas

Reflector grid antenna designed for long-range operation (line of sight & <7 mile) and can be configured for either vertical or horizontal polarization. UCONN Story.

Heavy-duty yet lightweight construction and a UV-inhibited powdercoat finish.

Know your “Beam Pattern” or “Coverage” Horizontal/Vertical discussion

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B. Radome-Enclosed Yagi Antennas

Radome-enclosed yagi antennas combine high gain and wide beamwidth in a compact package.

Solid aluminum boom and elements enclosed within a white UV-inhibited radome for all-weather operation

“Pringles-Can” / War Driver article…

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C. Omni-Directional 10db / 14 db Antennas

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D. Patch/Panel Antennas

Patch antennas are suitable for indoor and outdoor use. They are designed to be compact and aesthetic.

Narrow and wide beam avail. Point to Point vs. AP “Bow-tie” beam pattern

Low Price

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E/F. Planar Array Panel Antennas

Offers an attractive solution (aesthetics) for fixed subscriber and base station applications,

High performance alternative to Yagi-style antennas

Low Price Indoor/Outdoor

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G. Mobile Antennas

Feature a variety of gain, radiation pattern and physical mounting options.

Moving Vehicle Applications

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H. Indoor Ceiling-Mount Antennas

Ceiling-mount antennas are high performance, aesthetic and nearly invisible against a suspended ceiling.

~3db gain

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I. "Rubber Duck" Antennas

Perfect for portable applications and as replacement antennas for many popular access points

Laptops with built-in antenna $1100-$2000 price range today

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Active Ethernet (PoE) 

Active Ethernet eliminates 110v AC outlet installation @ AP.

“Injects” DC power onto the Ethernet (CAT5/5e/6) cable on Pins 7&8 (unused by Ethernet .

19” Rack Mount - 12 / 6 / 1 Port Available. Cisco WS-3524-PWR - WILL NOT support

this feature with out “Injector” hardware. (prop scheme)

Watch for 802.3ae!! 3COM 1st out of gate.

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D.U.’s Implementation:Agere/Orinoco & Cisco VPN

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Wireless LAN / WAN - 802.11b

Today’s predominant wireless ethernet IEEE Standard 2.4 GHz Carrier Frequency Uses “Direct Sequence” Radio Scheme Signals @ 4 speeds:11, 5.5, 2 & 1 Mb/sec 14 Channels/frequencies within 2.4 GHz Only 3 channels do not overlap (1, 6 & 11) Largest market share today Uses: for Pt-Pt, Pt-MPt & LAN Applications

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802.11b: Security & AccessOSI Layers 1 & 2

ESS (Network) ID: Text Constant Variable Standardized names by Summer ’02

Users can’t match name to location…. Moving from current 5 names to 1 standard

Orinoco Implements an Open / Closed setting:

Windows XP uses to help configure network. CLOSED = Does not broadcast ESSID OPEN = ESSID Broadcasted = **DU USING NOW**

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802.11b: Security & AccessOSI Layers 1 & 2 – Cont.

MAC Address Registration (on APs) Cumbersome & high management overhead Must re-enter if card is swapped out DU tried on 3 networks…...it’s over

Not using L2 WEP Key encryption

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802.1X - EAPLayer 2 Authentication Drafts 7,8 & 10 on table – None Approved Today. WEP works WITH 802.1X Solution for Wired Network:

Cisco CAT OS 6.x+IOS 12.1+

TypesClient

OS AP Radius Server Support

EAP TLS (transport level security)

WIN2K & XP

AP-2000/AP3 (ONLY MODE SUPPORTED)

Cisco Secure 3.0 NT & MS Active Directory

Certificate Server / Smartcard (no challenge-response)

Cisco 340/350

EAP TTLS N/A ? Funk Software onlyONLY the Server has to have cert.AP to Radius Server - Clinet does not care (USES TLS)

EAP Radius ? ?

EAP MD5 XP Cisco OnlyCisco Supports

LEAP (cisco Version draft 10) N/A Cisco Only Lightweight EAPOnly Cisco AP SupportedAny Cisco Wireless Card (download)

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Encryption Options:

Layer 2 – WEP (hardware based) Easily deciphered with sniffing software

WEP Key is “Static” Dynamic WEP – Solves static key problem

Evolving standard – proprietary methods today

DU transitioning to VPNs (IP Sec) now

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802.11b: Encryption & Access Using VPNs

VPNs: DU using Cisco 3030s to terminate VPNs Configured for IPSEC-3DES – 168Bit

VPN Client software leverages a back-end USER database for AAA functionality RADIUS: Radiator on Solaris 8

Cisco / DU Branded VPN Software for: Windows (98/ME/NT4/2K/XP) MAC OS 10 Solaris Linux

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Physical Network Topology DU Data Backbone Wireless is several Internal VLANs / Subnets

VLAN110

VLAN111

VLAN114

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VLAN 110

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VLAN 111

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VLAN 114

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Typical Proposed Wireless

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Future Wireless LANStandards to Watch

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IEEE - 802.11g

Doubles bandwidth with same RF characteristics

Extends 802.11b (2.4 GHz) to 22 M bit/sec.

Intended to be backwards compatible w/ 802.11b

Approved. 1st Products expected 2002

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IEEE - 802.11a Uses 5 GHz Carrier Frequency 6M–54M Bit /sec rates (54-100!) Different Radio A.P. Design Criteria (4x rule):

802.11b = ~250-300 Feet 802.11a = ~90 Feet Harder to get through walls, furniture, etc..

PC Cards will use more power – (Laptops) Products available today Total Cost of Ownership increases!

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IEEE - 802.11e - Draft AKA Whitecap2 – Cirrus Logic

Earliest incarnation of IEEE 802.11e

New standard proposal will add: QoS Features Multimedia Support to 802.11a &

802.11b Major improvements in overall “channel

robustness”

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802.11e – Cont.

Mechanisms for dealing with adjacent subnets operating on the same channel

Baseline Approved in November 2000 Final Draft expected in Late 2002 Final Approval is after Draft

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Product Links

Agere = AP2000/1000/500 http://www.lucent.com/micro/ Avaya = AP-3 = Agere AP-2000

Cisco = AP350 http://www.cisco.com/warp/public/cc/pd/witc/a

o350ap/ Antenna Resale

http://www.hyperlinktech.com/web/antennas_2400.html

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Other Good Articles & Links

http://standards.ieee.org/ http://www.wi-fi.com/ http://www.wireless-integration.com http://www.80211-planet.com This Presentation:

CHECO WEBSITE – SOON!

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Questions and Answers