1 university of washingtoncomputing & communications backgrounder for policy discussions on...

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University of Washington Computing & Communications

Backgrounder for Policy Discussions on Wireless

Terry GrayDirector, Networks & Distributed Computing

Scott MahDirector, Communication Technologies

February 2004

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Outline

• Generalities

• Technology Issues

• Policy Issues

• Funding Issues

• Bandwidth Issues

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Wireless is...• Addictive (users love it)• Seductive (appears to be cheaper/easier than it is)• Expensive to scale to an enterprise-class solution• Encouraging enclaves, balkanization• Rapidly changing technology• Hard to control• Hard to secure• Either parasitic upon, or synergistic with,

overall campus network infrastructure• Best seen as needing to parallel history of deployment of

Internet at the UW• Becoming mission-critical

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Key Issues

• Central vs Departmental wifi coexistence

• Technical standards

• Unauthorized access points

• Security policies (protecting others)

• Access control policies (who can use?)

• Funding and accounting policies

• Rented space, student-owned equipment

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Technology Issues• Standards

– IEEE 802.11a, b, e, f, g, h, i (and more!)– IEEE 802.1x, LEAP, PEAP, TLS, TTLS

• Monitoring, management• RF propagation, interference, pwr mgt• Security, access control• Performance, QoS• Availability, Reliability• Convergence

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Agenda for 1/2003 IEEE meeting

5.81.33.51.522.021.521.522.022.55.06.56.51.57.01.0

802.11 Working Group Meetings

802.11 Wireless Next Generation Standing Committee

802.11 Chair's Advisory Committee

Task Group G (802.11b Data Rates >20 Mbit/s)Task Group F (Inter-Access Point Protocol)Task Group E (MAC Enhancements - QoS)

802.11 / 15 /18 / 19 New Members Orientation Meeting

Joint 802.11 / 802.15 / 802.18 / 802.19 Opening Plenary

802.11 High Throughput Study Group

Task Group I (Enhanced Security Mechanisms)Task Group H (Spectrum Managed 802.11a)

Joint 802.11 / 15 / 18 /19 Lead Co-ord Ad-Hoc

Task Group K (Radio Resource Measurements)

Joint 802.11 / 802.15 Publicity Standing Committee

Task Group J (4.9 - 5 GHz Operation in Japan)

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Impact of VOIP over Wireless

• Separate backbone?

• Campus-wide roaming?

• Quality/Reliability expectations?

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Policy Issues

• Access control• Departmental/private nodes• Who, if not C&C under U-TAC policy

direction, owns/controls RF spectrum?• Who defines standards and minimum security

and coexistence policies?• Who enforces standards & minimum security

and coexistence policies?• How will an extensible, scalable and

sustainable model be established

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Central vs. Departmental Tensions• C&C not out front (we’d say not able to be :-)

• Inconsistent access policies (private enclaves)

• Inconsistent or non-existent security provisions

• Inconsistent or incompatible technology

• Inconsistent upgrade & maintenance policies

• 24-7 management

• Integration with central network infrastructure

• Integration with central authentication infrastructure

• Risks to central net infrastructure and nearby hosts

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Private Wireless Nodes on the Campus Net

• Rationale:– Central service not available– Central wireless service too expensive (can plug

cheap wireless access point into campus net)– Central service sometimes more inconvenient for

visitors– Central service is an attractive nuisance – Very special research requirements– Special security requirements

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Funding Issues

• Central, departmental, subscription (voluntary or mandatory), STF...

• One-time ‘Capital’ always easier to find than operating $$

• Recharge strategies incent rogue systems

• Dealing with rogue access points dramatically increases operational costs and security dangers/costs

• Department & STF deployments drive costs they don’t pay (‘coping and cleanup is an unfunded mandate’)

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Cost Factors

• Degree of convergence– wired and/vs. wifi data vs. wifi telephony

• Security & access control

• Technology immaturity, churn• Management & accounting features (exact

parallel to routers and e-net switches etc, but harder!)

• User support

• Scaling (+ and - economies of scale)

• Sustainability

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Essential Capital Cost Elements

• Physical facilities (e.g. power, cooling, pathways, equipment space and antenna space)

• Wireless Access Points (WAPs)• Dedicated subnets for wireless (wired Ethernets

to WAPs, switches, routers, security boxes, etc.)

• Access point management system

• Authentication system

• Authentication management system

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Operational Cost Elements• UW Staff

– Design– HW Installation and SW Configuration/updating– Monitoring and reporting– Troubleshooting– Security incident handling (harder w/wireless)– User Support– Sustaining underlying ‘wired’ net. infrastructure

• Vendor– Maintenance & Upgrades (firmware, SW and HW)

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Case Study: MGH (a new and very well wired facility)

• Size: 99,000 ASF

• Classrooms: 27 + 12

• Floors: 4

• Access Points: 36

• Initial Cost: $94,000

• Initial Cost per Classroom: $2,500

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Bandwidth Consequences• Wireless implies many more computers, PDAs, hybrid

cell/802.11 devices, etc.• Steady growth (or maybe even spike, esp. with ‘net

generation’ students) in network devices• Bandwidth needs track:

– users– usage– apps and objects– capacity

• Wireless capacity constrains types of apps (for now)

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Performance Comparison [from early 2002; Gig Ethernet can now exceed 900 Mbps ]

From www.extremetech.com

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Network Device Growth

Note: Most dips reflect lower summer use; last one is a measurement anomaly

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Network Traffic Growth (linear)

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Network Traffic Growth (log)

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Outcomes to Avoid

• Unrealistic security expectations

• Department wireless deployments that...– Confuse users re: who supports what– Interfere with or destabilize campus network– Create extra threats to others– Balkanize net services w/conflicting policies– Drive U-wide costs no one is underwriting

• Non-scalable or non-sustainable models

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Questions? / Comments?

1 university of washingtoncomputing & communications backgrounder for policy discussions on...

Documents

central net infrastructure

access control policies

campus net central service

visitors central service

coexistence policies

ieee meeting slide

reliability convergence

missioncritical slide