Transcript Wireless Networking Update University of Denver

DU Wireless
Networking Update
Chad D. Burnham & Byron D. Early
University Technology Services
July 9, 2002 @ Univ. of Utah
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Why Wireless @ DU? Laptops!
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Laptop Requirement @ DU:
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Students learn to utilize technology WHILE
learning educational content
‘02-’03: All undergrad & MBA students required
to have laptops with wired 10/100 Ethernet card.
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Undergraduate Laptop program in place since Fall ’99
Laptops showing up with 802.11b cards built in.
Students are asking about where & how on campus.
Why Wireless? (Cont.)
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~5000+ student laptops on & off DU
network
~300 faculty use laptops via departments,
grants (some self funding)
Student Survey Results:
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More “wireless hotspots”
Laptop Technology in DU’s
Curriculum
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Wireless network access is an overlay network
service designed to provide physical flexibility in:
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Center for Teaching and Learning (CTL)
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Academic grants used as incentives for divisions to
‘convert’ to digital media.
DU’s Blackboard On-line Class Implementation
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Open Areas – “Hot Spots” (inside & outside)
Wired Classrooms
Homework, Syllabus, Class Notes, PowerPoint
Slides, quizzes.
Wireless Technology Concerns @
DU
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Bandwidth limitations:
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Privacy & Security
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Performance: Not adequate for certain applications
Encryption & Authentication
Network Snooping – Separate VLANs for Wireless
networks (not ‘on-top’ of existing)
Technical Support / People:
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Card Installs: its all about the “DRIVERS” 
VPN Software: Installation/configuration
User password issues
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AD / LDAP / Kerberos?
Wireless Technology Concerns @
DU - Continued
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Evolving/changing wireless technologies & PC
operating systems:
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“Rogue” Access Points – Dept. Installed
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Incompatibilities with installed base
Upgrade costs
Security Issues – Network Access
Performance Issues (Duplex)
CDW ad: “I can do wireless”, “what is wireless”?
Top Level policy in draft stage - How to police?
Wireless Network Benefits for DU
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Convenience
Places you cannot wire
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Flexibility physical group learning models
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Historical buildings
Access problems
Cannot get fiber uplink to
New type of “smart-classroom”
The Ricks Center
(DU’s private K-8 school)
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First wireless system was proprietary infrared technology:
Summer 2000
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Not well liked or successful (connect problems, lost sessions, etc.)
Replaced with 802.11b Network:
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72 Laptops Provided to students by Ricks Center
4 x 802.11b Access Points
Security: MAC Address Registration & WEP
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High administrative overhead
Works well in this closed environment
Content Management in place
The Ricks Center (Cont.)
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Reasons for Implementing Wireless for K-8
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Classes frequently broken into small “work
groups”
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Group & individual research flexibility
Web Publishing application
E-mail
Lower bandwidth type applications
Rick Center: Continued
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Purchased mobile Dell Cart to secure units
Penrose Library
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(10) 802.11b Access Points Installed
Redefining the library….
Provides for wireless access for students, staff and
faculty in library
“Wireless Festival”
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VPN tested with 25 laptop users
Ready for “prime time” by fall 2002
Expanding Wireless @ DU
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Current Installed Base:
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Summer Projects 2002:
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70 total Access Points in (18) VLANs
Security: In process of implementing VPN
Adding (30) Access Points = 90 Total
VPN-Only Access for all wireless
21 total VLANs
So now you want to build a
wireless network?
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“The RF Site Survey”
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Outside Firm vs. In-House
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Dictates # of APs and placement of APs
(RF Design)
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Outside Costs: ~$100 per/hr per/person
DU tried 2 different firms – limited use now
Gives initial grasp of hardware & installation
costs
Site Survey
Recommendations:
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Use 3 people to do the surveys:
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1 person @ proposed base area with AP & various
antenna types
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2 people on wireless laptops (w/802.11x radio) &
handheld walkie-talkies
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Documenting SNR (in software) – to be overlaid on to
maps/floor plans.
Cannot do “valid” site-surveys from blue-prints
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Changing Antennas type/position/location
Documenting results
New buildings: radio waves propagate much
differently with furniture and people present
Site Survey Recommendations:
(Cont.)
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Assemble “Site Survey Tool Kit”
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Detailed layout/blueprints of building
Portable battery pack for AP
AP & Radio Cards: use same brand as
equipment to be deployed
Variety of Antenna types
Misc: digital camera, tie wraps & tape,
flashlight, etc.
Antenna Placement
Recommendations:
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Do not place antennas near:
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Separation important with multiple antennas
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Metal objects (filing cabinets, railings, I-Beams, lath,
pipes, etc.)
Walls (when possible; unknown construction)
Wave degradation issues
1 meter when on same tripod mast
Antenna should be placed in accessible area
Rooftops: Denver building code requires coax in
rigid conduit supported off the roof (stands)
Antennas (Cont.)
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Think 3-Dimensionally
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Keep coax / LMR waveguide to minimum
length
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“Outside In” Approach (contain signals in
desired area)
Patterns vary by antenna type
Horizontal & Vertical “beam patterns”
Move the data cable & AP before making
coax longer
Wave Guide / LMR COAX
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Cabling from Antenna to Access Point
LMR 200/400/600/800, etc. = Size & Loss
Properties
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LMR have very low signal loss properties
Every Db matters: Keep distances as short as possible
Newer Balun (75 <-> 50 Ohm) & Amplifier combo units
available to deliver over cheaper RG-6 Coax
Times Microwave: Industry leader in cable, prep
tools, and connectors.
Coax (Cont.)
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“Leaky Feeder Coax”
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Used as “base-station” antenna
“Leakage Slots” in outer foil conductor
Applications: vehicular tunnels, mines, inside
buildings
Sized as LMR 600
Expensive
 Performance: DU has not tried yet
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Antenna Variables to look for:
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Antenna Data Sheet: read, understand, be
skeptical (assume ½ coverage to be safe)
Beam Coverage:
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Antenna gain: rating in Dbi. (extends tx/rx “range”)
Size/Shape
Aesthetics
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Horizontal & Vertical (in degrees)
Remember: must have line of sight!
Cost
2.4 GHz rated (802.11b)
RF: Its all in the Antenna….
A.
B.
C.
D.
E.
F.
G.
H.
I.
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Parabolic Grid Antennas
Radome-Enclosed Yagi Antennas
Omni Directional Antennas
Patch Antennas (Bow-Tie)
Planar Array Panel Antennas
Heavy-Duty Panel Antennas
Mobile Antennas
Indoor Ceiling-Mount Antennas
"Rubber Duck" Antennas
A. Parabolic Grid Antennas
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Reflector grid antenna designed for longrange 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”
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Horizontal/Vertical discussion
B. Radome-Enclosed
Yagi Antennas
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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…
C. Omni-Directional
10db / 14 db Antennas
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D. Patch/Panel Antennas:
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Patch antennas are suitable for indoor and
outdoor use. They are designed to be
compact and aesthetic.
Narrow and wide beam avail.
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Point to Point vs. AP
“Bow-tie” beam pattern
Low Price & excellent performance!
E. & F. Planar Array Panel
Antennas:
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Some models offer an
attractive solution
(aesthetics) for fixed
subscriber and base
station applications,
High performance
alternative to Yagistyle antennas
Indoor/Outdoor
G. Mobile Antennas
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Feature a variety of
gain, radiation pattern
and physical
mounting options.
Moving Vehicle
Applications
H. Indoor Ceiling-Mount Antennas
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Ceiling-mount
antennas are high
performance,
aesthetic and nearly
invisible against a
suspended ceiling
(Holocom Panel)
~3db gain
I. "Rubber Duck" Antennas
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Perfect for portable
applications and as
replacement
antennas for many
popular access points
Active Ethernet (PoE)
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Active Ethernet eliminates 110v AC outlet
installation @ AP.
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“Fault protected” recommended
“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 without “Injector” hardware.
802.3af ratified (today: 3Com, Milan).
D.U.’s Implementation:
Agere/Orinoco & Cisco VPN
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DU: 802.11b (Current Networks)
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802.11b: Today’s most prevalent
wireless Ethernet IEEE Standard
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2.4 GHz Carrier Frequency
Uses “Direct Sequence” Radio Scheme
Signals @ 4 speeds:11, 5.5, 2 & 1 Mbps
14 discrete Channels/frequencies
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Applications:
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Only 3 channels do not overlap (1, 6 & 11)
LAN, Point-to-Point, Point-to-Multi-Point
DU: Future Wireless Networks
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802.11g (2.4 GHz, 22 Mbps)
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Orinoco AP-2000 supports b & g in same box
Antenna Placement Remains the same
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802.11a (5 GHz): Higher frequencies require more
antennas for same coverage
802.11b: Security & Access
(OSI Layers 1 & 2)
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ESS (Network) ID: Text Constant Variable
 DU: Using Single Standardized Name
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Users can’t be expected to know multiple wireless
names for different locations
Open vs. Closed Network Setting (BSS):
“Open Setting”: Used by Windows XP to configure
network automatically (pros and cons)
 “Closed Setting” does not broadcast ESSID (weak
security, user must know ESSID)
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802.11b: Security & Access
OSI Layers 1 & 2 (Cont.)
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MAC Address Registration (on APs)
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Cumbersome & high management overhead
Must re-enter if card is swapped out
DU tried on 3 networks…...it’s over
DU Not Using: L2 WEP/WEP2 Key encryption
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WEP2 (802.11i) not yet ratified
DU using VPN layer 3 solution
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Encryption & AAA
802.11b: Security & Access (Cont.)
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“Open” Access Points:
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Mapped & Published on
the Web
“Warchalking”: Do the
outside walls of your
wireless buildings have
unusual graffiti?
DU Encryption & Access Using
VPNs:
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VPNs: DU using Cisco 3030s to terminate VPNs
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Configured for IPSEC-3DES – 168Bit
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Authentication & Authorization: VPN Client software
leverages a back-end USER database for AAA
functionality
 RADIUS: Radiator on Solaris 8
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DU “Branded” Cisco-VPN Client Software for:
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Windows (98/ME/NT4/2K/XP)
Not Yet DU-Branded:
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Pocket PC, Palm OS, MAC OS 10,Solaris, Linux
“Locking Down” Wireless LANs:
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Router Access Control List Objectives (so far):
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# Allow IPsec to VPN Concentrators
#Allows MSFCs to see each other for HSRP
# Allow bootp on broadcast
# Allow bootp from DHCP clients
# Allow DNS to iVPN DNS server
# Allow download of client
# Allow MGMT station to ping router and AP's
# Allow these systems to be pinged
#Allow management station to snmp from APs
# Deny all else
University of Denver
Wireless LANs
Outdoor Antenna Grounding Diagram
Antenna
(typ.)
Tri-pod/Mast
Legend
LMR
Grounding Kit
GK-S400
6 AWG Bare
Copper
LMR 400
COAX
Roof Top
Antenna
Practices
Antenna_Ground
1"
Copper
Water
Pipe
Clamp
Edit Date: 5/28/02
Rev: 1.2
Filename:Wireless Install.vsd
Creator: cburnham
Company: DU = UTS/NS
Plywood Backboard
Power Strip
Pigtail
Wireless
AP
Surge
Arrestor
Copper Bus-Bar
Copper Bus-Bar
LMR-400
(In Flex-Tubing)
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Surface J-Box
(use Caulking)
Roof Top
Antenna
Practices cont:
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In-Ceiling
Antenna
Practices
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Physical Network Topology
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DU Data Backbone
Wireless is several Internal VLANs / Subnets
VLAN
7XX
VLAN
6XX
VLAN
8XX
VLAN
9XX
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VLAN 110
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Typical Proposed Wireless
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Standards Watch:
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DU: Standards-based solution
802.1X - EAP
Layer 2 Authentication
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Drafts 7,8 & 10 on table – None Approved Today.
WEP works WITH 802.1X
WEP2 not expected to be ratified until 2003
Solution for Wired Network:
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Cisco CAT OS 6.x+IOS 12.1+
Types
EAP TLS (transport level
security)
Client
OS
WIN2K &
XP
Certificate Server / Smartcard
(no challenge-response)
EAP TTLS
ONLY the Server has to have
cert.
AP to Radius Server - Clinet
does not care (USES TLS)
EAP Radius
EAP MD5
Cisco Supports
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LEAP (cisco Version draft
10)
Lightweight EAP
Only Cisco AP Supported
Any Cisco Wireless Card
(download)
AP
Radius Server Support
AP2000/AP3
(ONLY
MODE
SUPPORTE Cisco Secure 3.0 NT & MS
D)
Active Directory
Cisco
340/350
N/A
?
?
?
XP
Cisco Only
N/A
Cisco Only
Funk Software only
IEEE - 802.11g
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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.
Products expected Q3 2002
IEEE - 802.11a
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Uses 5 GHz Carrier Frequency
6M–54M Bit /sec rates (54-100!)
Different Radio A.P. Design Criteria (4x rule):
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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!
IEEE - 802.11e:
 AKA
Whitecap2 – Cirrus Logic
 Earliest
 New
incarnation of IEEE 802.11e
standard proposal will add:
 QoS
Features (multi-media, voice, etc.)
 Applies to 802.11a, 802.11b, 802.11g
 Major improvements in overall “channel
robustness”
 Deals with adjacent subnets operating
on the same channel
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Ratification expected Q3 2002
IEEE – 802.11i:
 New
standard proposal will add:
 Enhanced
WEP (a.k.a. WEP2)
 Applies to 802.11a, 802.11b, 802.11g
 New encryption & authentication methods
 Temporal Key Integrity Protocol (TKIP)
 AES (an iterated block cipher) and TKIP
backwards compatibility.
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Ratification expected Q3 2002
IEEE – 802.11f:
 New
standard proposal will add:
a
"recommended practice" document
 “Roaming” Interoperability between
vendors:
 Defines
registration of access points within
a network and interchange of information
between access points when a user is
handed over from one access point to
another.
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Ratification expected Q3 2002
IEEE – 802.11h:
 New
standard proposal will add:
 Supplementary
standard to MAC layer in
order to comply with European regulations
for 5GHz WLANs.
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Ratification expected Q3 2002
Product Links:
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Agere (Orinoco) = AP2000/1000/500
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Cisco = AP1200
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http://www.cisco.com
Antenna Reseller:
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http://www.agere.com
Proxim bought Agere 6/2002
http://www.hyperlinktech.com/web/antennas_
2400.html
Other Good Articles & Links
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http://standards.ieee.org/
http://www.wi-fi.com/
http://www.wireless-integration.com
http://www.80211-planet.com
This Presentation:
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Will make available on Westnet site
Questions ??? and Answers ???
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