university of washingtoncomputing & communications campus network design: wired vs. wireless...

University of Washington Computing & Communications

CAMPUS NETWORK DESIGN:Wired vs. Wireless

Terry GrayDirector,

Networks & Distributed ComputingUW Computing & Communications

September 2001


Scope of UW Networking• UW Campus Networks

– Seattle– Tacoma– Bothell/CCC

• Medical Centers (net design)– UW Physicians Network– UW Medical Center– Harborview Medical Center

• Pacific/NorthWest Gigapop– Pacific Wave exchange point– Pacific Light Rail

• Statewide K20 Network


Pacific Northwest Gigapop


Baseline Connectivity

• Shared 10Mbps HD

• Switched 10Mbps HD

• Switched 10/100Mbps FD– backed by GE switch/router infrastructure

• Goal: Switched 10/100 FD for all; GE for a few

• Reality: Cat3 wireplant upgrade will take multiple years and multiple millions of dollars


Advanced Services• Multicast

– Partially deployed– Older routers need to be replaced

• QoS– Laissez faire? Premium service?– Best with FD connections.

• VoIP– Needs QoS, extra-high availability– POE desirable; implies UPS in closets

• IPv6


Premium Services?

• Wide-area QoS chargeback?

• Preferred access to Internet for a fee?

• Lots of interesting policy and tech issues...


Mistakes We Didn't Make

• FDDI to the desk• VLANs• ATM• Various "cut-thru IP switching" digressions

• Claim: Staying with pure IP and Ethernet has served UW very well...


Current Statistics• Avg Backbone traffic: nearly 2 TB/day• Peak Inbound traffic: 100 Mbps (40 in 1999)• Peak Outbound traffic: 160 Mbps (20 in 1999)• Doubling time: Less than 2 years!!• Hosts: over 50,000• Modems: over 2,000• Switched subnets: 70% (30% in 1999)• 10/100 FD subnets: 25% (5% in 1999)• Cat 5 buildings: 10%


UW-S Building/Subnet Status

Depts Dorms Hospitals TOTAL

Buildings 193 Cat 3 175 Cat 5 18

Subnets 269- 41 - 310

10Mbps 85 100Mbps 1311000Mbps 94


GigE Buildings

• Physics/Astronomy• Fisheries Center• new Ocean• Lander Hall• McCarty Hall• Parrington Hall• Edmondson Pavillion• Mary Gates Hall• OUG Library

• part of Electrical Engr.• part of HS K wing• part of HS T wing • part of Johnson Hall• part of Savery• part of Thomson Hall• part of 4545


Simplified Network Topology

Router Router

BorderRouter

CoreSwitch

EdgeSwitch

Edge Switch

InteriorSwitch

InteriorSwitch

Gigapop Internet2

DesktopDesktop

Internet

Fed Nets4

30

300

1000+Branch Site

50,000

PBX


Number of Devices


Backbone Traffic


Border Traffic 1999


Border Traffic 2001


Recurring Theme: Explosive Growth

• More users• More devices• Longer use• New (bandwidth-intensive) applications

– e.g. remote collaboration tools– audio/video streaming– tele-immersion– distance learning


Networking Hot List• Campus building/subnet upgrades• Backbone upgrades (production, experimental)• Regional networking• Network Hardening• Security• Advanced Services• Wireless• Management/diagnostic tools


Success Metrics

• 10/100 FD connections: xx%

• Multicast deployment: xx%

• QoS deployment: xx%

• Dept’l wireless coverage: xx%

• Router center hardening: xx%

• Backbone capacity

• IPv6 capable routers


On to Wireless...


Wireless Categories

• Wireless by Purpose– Point-to-Point links– Access networks

• Wireless by Spectrum– Infrared– RF– Optical


Wireless RF by Range• PAN/HAN (Personal/Home-Area-Network)

– Bluetooth– HomeRF

• LAN (Local-Area-Network)– IEEE 802.11– ETSI HiperLAN2

• MAN (Metro-Area-Network)– LMDS, “Fixed Wireless”

• WAN (Wide-Area-Network)– Ricochet (R.I.P.)– CDPD– 2.5G, 3G, etc, etc, etc


LAN Wireless Standards

• IEEE 802.11 2.4GHz, 1-2Mbps, FHSS, DSSS

• IEEE 802.11b 2.4Ghz, 11Mbps DSSS (WiFi)

• IEEE 802.11a 5Ghz, 54Mbps

• ETSI HiperLAN2 5Ghz, 54Mbps, TDMA

• In US, all use unlicensed “ISM” bands


802.11 ISSUES

• Network Design, esp. Topology

• Access control

• Security

• Compatibility

• Interference

• Relation to Bluetooth, HomeRF, etc

• Obsolescence


ROAMING ISSUES

• Layer 2 (802.11) vs. Layer 3 (Mobile IP)

• Vendor incompatibility

• LAN vs. WAN

• We will support L2 roaming within a building by dedicating one subnet for all access points in the building.


Policy Issues

• Part of campus network infrastructure

• Want to encourage small-scale deployments with minimum overhead, but coordination needed to avoid interference

• Large-scale deployments need to be coordinated by C&C

• Campus-wide access control policy


UW-S Wireless Deployment

• C&C Pilot Project– Kane Hall, Rm. 130– Mary Gates Hall– Gerberding Hall– Odegaard Undergraduate Library

• Other wireless projects– CS, C&C, Business, MCIS, ...


Pilot Project Objectives

• Provide 11 Mb coverage throughout selected facilities.

• Allow roaming within facility space.

• Develop suitable policies.

• Gain operational experience.


Pilot Project Lessons Learned

• Success depends on cooperation w/dep’ts

• It takes more wire than you think!

• Site surveys & frequency sweeps needed.

• WEP is not secure; use SSH, SSL, etc.

• Technology still evolving

• 2.4GHz phones interfere badly


Wired vs. Wireless Issues

• Server suitability• Performance• Performance variation• Price/Performance• Interference• Technology maturity• Advanced services• Security


802.11a: Successor?

• Faster• Shorter distance• More power consumption• Probably won’t replace 802.11b• Probably need WAPs for both


Infrastructure Requirements

Phones Wired Wireless

Closets YES YES YES

Conduit YES YES YES

Wireplant YES YES Much

Switches Maybe YES Some

WAPs NO NO YES


Conclusions

• Wireless is very addictive.

• It will be very popular.

• It will be very problematic.

• The dust has not settled.

• In offices, it is not a replacement for wired.

• In classrooms, lounges, etc, it is… but that still requires some wired infrastructure.


Wireless References• Open Group: www.openwirelessdata.org• Wireless Ethernet Compatibility Alliance (WECA)• Wireless LAN Association (WLANA)• Portable Computer & Communications Association (PCCA)• Internet Engineering Task Force (IETF)• WAP Forum• Bluetooth Special Interest Group• Mobile Wireless Internet Forum (MWIF)• Wireless Information Networks Forum (WINForum)• HiperLAN2 Global Forum• Wireless Data Forum

university of washingtoncomputing & communications campus network design: wired vs. wireless...

Documents

pbx slide

closets ipv6 slide

mbps fd

johnson hall

thomson hall

mbps hd

peak outbound traffic

fd subnets