Cisco press the business case for enterprise class wireless LANs may 2006 ISBN 1587201259

Publisher: Cisco Press Pub Date: May 16, 2006 Print ISBN-10: 1-58720-125-9 Print ISBN-13: 978-1-58720-125-7 Pages: 456 Table of Contents | Index A comprehensive guide to analyzing the b

The Business Case for Enterprise-Class Wireless Lans

By H David Castaneda, Oisin Mac Alasdair,Christopher A L Vinckier

Publisher: Cisco Press Pub Date: May 16, 2006 Print ISBN-10: 1-58720-125-9 Print ISBN-13: 978-1-58720-125-7 Pages: 456

Table of Contents | Index

A comprehensive guide to analyzing the business rationale for WLANs

Evaluate the business rationale behind the deployment of WLANs, including return on investment (ROI), net present value, payback period, and total cost of ownership Develop a robust execution plan to deploy and operate the WLAN

Understand the high-level technical issues of deploying and managing your WLAN from a business decision-maker's perspective

Maximize the positive impact of supplementary and complementary services such as voice, video, and guest WLAN access

Identify potential security threats and develop strategies to mitigate attacks

Learn methodological and technical best practices from WLAN deployment case studies featuring real-world, enterprise-class businesses and institutions

Gather information easily by referring to quick reference sheets and appendixes covering an antenna overview, a high-level sample project plan, checklists, and flowcharts

Businesses today are increasingly adopting wireless LANs (WLANs) as a primary data transport mechanism To determine when and how to effectively deploy WLANs, business managers, project managers, and IT executives need a clear, holistic evaluation of the business benefits and risks behind this complex technology solution.

The Business Case for Enterprise-Class Wireless LANs helps you make the right decisions

architecture to deployment and application Using a lifecycle perspective, this guide covers the value proposition, cost justification, and alignment of security, design, and operational components within the business.

Written in an approachable style, The Business Case for Enterprise-Class Wireless LANs

provides a baseline analysis of WLAN technologies for a large-scale deployment and

includes concise real-world case studies with checklists and flowcharts that you can adapt for your needs By recognizing the obstacles and advantages of implementing a WLAN from a strategic and justified business perspective, you can apply the economic benefits to your organization and ensure a timely and efficient deployment of your organization's WLAN.

This volume is in the Network Business Series offered by Cisco Press® Books in this series provide IT executives, decision makers, and networking professionals with pertinent information about today's most important technologies and business strategies.

The Business Case for Enterprise-Class Wireless Lans

By H David Castaneda, Oisin Mac Alasdair,Christopher A L Vinckier

Publisher: Cisco Press Pub Date: May 16, 2006 Print ISBN-10: 1-58720-125-9 Print ISBN-13: 978-1-58720-125-7 Pages: 456

Index

information storage and retrieval system, without written

permission from the publisher, except for the inclusion of briefquotations in a review

Printed in the United States of America 1 2 3 4 5 6 7 8 9 0First Printing May 2006

Library of Congress Cataloging-in-Publication Number:

2004104127

Warning and Disclaimer

This book is designed to provide information about wirelessLANs Every effort has been made to make this book as

complete and as accurate as possible, but no warranty or

fitness is implied

The information is provided on an "as is" basis The authors,

accompany it

The opinions expressed in this book belong to the authors andare not necessarily those of Cisco Systems, Inc

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trademark or service mark

H David Castaneda is a senior technical member of the Cisco

Systems Advisory Services group In this role, he is responsiblefor consulting with the top-tier customers of Cisco about thevalue and application of advanced technologies Before his

current role, David was the architect and technical lead for theinternal wireless LAN strategy and deployment at Cisco Duringhis eight-year tenure at Cisco, he has held various positions inthe United States and Europe

Oisin Mac Alasdair is an IT program manager with the Cisco

Intelligent Network Solutions group within IT infrastructure.Oisin has been responsible for the Cisco enterprise wireless

strategy and architecture for the past six years He continues todefine Cisco IT's wireless direction and represents Cisco IT'sstrategy and vision for wireless technologies to customers, themedia, and the business Before joining Cisco, Oisin had severalarchitectural and consultancy roles with Fortune 100 companies

in the finance and IT industries in the Asia-Pacific region andEurope Oisin is the proud father of a brand new baby girl and is

a loving husband to his beautiful Australian wife

Christopher A L Vinckier is an engagement manager with

the Cisco Systems Advisory Services group In this role, he

assists customers in solving the perennial problems of businesstechnology alignment, adoption, and absorption He has advisedseveral of the largest Fortune 500 customers of Cisco on thestrategic, operational, and financial benefits of IP-based

infrastructure solutions Christopher holds an MS in computerengineering from the University of Ghent, Belgium and an MBA

in finance from MIT's Sloan School of Management

wireless implementations for customers such as Wal-Mart, Ford,Hertz Rent-ACar, and Kroger Fred has been in the data

communications and networking industry for the past 20 yearsand holds a Radio Amateur (Ham) License "N8CPI."

Jack Unger, founder and president of Ask-Wi.Com, Inc., and

Wireless InfoNet, Inc., has served the broadband wireless

industry continuously since 1993 designing, installing,

troubleshooting, and optimizing wireless networks Jack alsoserves as a wireless-industry trainer and author His vendor-

neutral handbook, Deploying License-Free Wireless Wide-Area

Networks, was published in 2003 by Cisco Press In workshops

across the United States and Canada, Jack has personally

trained more than 1500 ISP personnel in the deployment ofoutdoor wireless networks.

Jim Schachterle deserves a tremendous amount of kudos for hiscontribution as the initial editor of this book In addition to

being knowledgeable, organized, flexible, and helpful, he alsowas an exceptionally patient coach in kick-starting this project

Mary Beth Ray did a superb job managing this project to theend Her positive attitude and receptiveness made our job a loteasier

Thanks to Raina Han for her belief in us, her inexhaustible

dedication to the project as the editorial assistant, her timelycracking of the whip, and her exquisite sense of humor

Thanks to Dayna Isley as the development editor of Cisco Pressfor her top-notch editing, attention to detail, and timeliness

The entire Cisco Press team worked tirelessly behind the

scenes We wish to thank everybody in editorial, illustration,layout, and the rest of the production team for their

Acknowledgments from H David Castaneda: I would like to

acknowledge the many people who, over time, have influencedand provided the opportunities that have made me a successtoday Personally I would like to acknowledge my fellow

Acknowledgments from Oisin Mac Alasdair: I would like to thank

my coauthors for their partnership, Bruce Scott and David

Renaud of Griffith University for their friendly assistance,

Sergey Shitov of Cisco IT for being an inspiration to work withand a world-class technical lead in the Cisco wireless space formany years, and Sarah, my ever-patient wife and mother to ourbeautiful new baby girl: "This one's for you, Niamh!"

Acknowledgments from Christopher A L Vinckier: I would like

to thank my parents for their dedication and for helping me getwhere I am today Dad continues to be the source of inspirationfor intellectual curiosity and Mom for instilling in me the pursuit

of excellence I also want to thank David and Oisin for makingthis project as fun as it has been, my friends from MIT for

bouncing ideas off and keeping me focused, and finally Lana forher patience, understanding, and support, and for making mestart every day with a smile

Finally, we want to acknowledge our friends at Cisco who havealways been very supportive of this effort We especially wish tothank our managers Mike Norman, Greg Duncan, Dave Evans,Stuart Doyle, Chris Webber, and Paul McNabb for their patienceand support

The conventions used to present command syntax in this bookare the same conventions used in the IOS Command Reference.The Command Reference describes these conventions as

follows:

Boldface indicates commands and keywords that are

entered literally as shown In actual configuration examplesand output (not general command syntax), boldface

Square brackets [ ] indicate optional elements

Braces { } indicate a required choice

Braces within brackets [{ }] indicate a required choice

within an optional element

Several good books have been written on the various technicalaspects of wireless local-area networks (WLANs), including

devices, networking protocols, and radio technologies Networkdesigners and administrators wanting to learn and apply thetechnical nuts and bolts of WLANs have no shortage of

reference material to consult

What is more challenging to find is a single reference on thelifecycle aspects of WLAN solutionsthat is, a guide that coversthe business considerations, which include the value

proposition, cost-justification, and alignment of security,

architecture, and operational components with the business Wewrote this book to address that shortage by examining WLANsfrom a lifecycle perspective The scope extends from the

identification of the business value that a WLAN can bring toyour organization to how to build and operate your enterprise-class WLAN

Today, the evolution of WLANs and the subsequent penetrationinto the enterprise market have moved faster than ever

expected This trend is expected to accelerate over the nextcouple of years However, the increased and accelerated up-take will not occur haphazardly Following the IT investmentfrenzy of the 1990s, scrutiny and accountability have becomethe new norms when it comes to evaluating and pursuing

technology investments Understanding the intricacies of a

technology provides little value when evaluating the businessbenefits that IT management requires Indeed, it is more crucial

organization should do in terms of architecture, deployment,and operation strategies

The nature of LANs has evolved to include the adoption of

wireless transport as a primary medium Today, enterprise-classequipment and solutions enable companies to pursue

aggressively an investment in wireless LAN technology

However, this relatively simple transport mechanism can quicklybecome complex when introduced into the enterprise

A holistic assessment of the opportunity to leverage WLANs in

an organization requires not only an in-depth understanding ofthe strengths and weaknesses of WLAN technologies but alsoidentification of opportune areas of application and legitimizing

of the use of WLANs in your specific organizational ecosystem.Economic considerations must be made, and various

methodologies and frameworks can be drawn upon to develop arelevant and robust WLAN business case This process will notonly ensure a comprehensive approach for the evaluation onWLANs but also increase the speed and accuracy of the

assessment of the business proposal by the key stakeholders

When the time comes to tackle the question of how to plan,design, implement, and operate a WLAN in a scalable, reliable,and secure fashion in your organization, it will quickly becomeclear that these domains are inherently strewn with barriers

The Business Case for Enterprise-Class Wireless LANs takes a

business approach to wireless networking This goal is achieved

by focusing more on strategic and business justifications andless on the intricacies of the underlying technology However, abaseline analysis of WLAN technology is included, empoweringyou to understand the complex technology-related decisionsdetailed later Most books on WLANs go into great technical

detail and are therefore off-putting to our audience Therefore,this book will not cover WLAN technology to that degree of

detail

offers guidance on how to identify and mitigate challenges

surrounding large-scale enterprise deployments Finally,

because real-world examples form a valuable baseline againstwhich to compare your specific WLAN consideration, variouscase studies of WLAN deployments in large organizations areincluded to complement and ground the theoretical

methodologies and frameworks

Objectives

Among the many concerns that arise when considering WLANsfor an enterprise environment, several are more common thanothers and clearly stand out These recurring apprehensionsinclude

WLANs in your organizations and develop a robust executionplan to deploy and operate the WLAN The book is not intended

as a highly technical guide for network engineers Instead, itsgoal is to provide upper and middle management with the

necessary technological understanding of WLANs to perform arealistic and sound assessment of WLAN investment and

exposing known risks, and imparting remediation techniques

For this purpose, the book leverages the PPDIOO technologylifecycle to construct a phased and exhaustive approach for

evaluating and managing the addition of WLANs to the IT

infrastructure portfolio The PPDIOO lifecycle methodology

consists of six distinct yet interlinked phases The phases are asfollows:

organization

Audience

This book focuses on how to understand, identify, and managethe value that WLANs can bring to organizations As such, it is

WLAN technologies The book primarily targets business andmanagement decision makers and those with the responsibilityfor architecture and deployment of enterprise-class WLANs Thebook provides advice to the decision maker on the business andhigh-level technical issues they should consider for evaluatingthe investment decision of deploying WLANs and ensuring thesound execution of the deployment of the WLAN

The audience for this book can thus be segmented into a

primary and secondary audience:

The primary audience consists of business decision makerswho shoulder the accountability for making the investmentdecision and ensuring the positive deployment and

operation thereof at the program level

The secondary audience consists of IT engineers and projectmanagers who are responsible for the actual deploymentand who want to strengthen their understanding of the

upstream decision-making process and best practices forWLAN deployments

The primary audience should possess a strong background inenterprise-level projects Executive-level readers should haveaccountability for long-term enterprise infrastructure projectand programs Competency in strategic planning, technologydelivery, and large-scale (global) deployment is highly

recommended An understanding of Ethernet and wireless

Ethernet technologies would be beneficial for technical

leadership readers

The secondary audience should have an understanding of thetarget market for WLANs and their benefits Although it is not anecessity, the secondary audience should have a basic

Organization and Approach

The Business Case for Enterprise-Class Wireless LANs focuses

on the decision making and business justification in addition tothe WLAN execution program management effort Throughoutthe book, you find reader-friendly descriptions, quick referencesheets, diagrams, and visual layouts that aid in explaining alltopics Case studies provide real-world touchpoints on the

topics discussed The book adopts a four-part structure, as

follows:

Part I, "The Fundamentals of Wireless LAN Strategic Planning," provides a succinct technical introduction to the

technology and concepts surrounding wireless networking.This section also outlines the strategic rationale and

business drivers that you will have to consider when

contemplating a WLAN deployment You will be given

explanations of how to construct a strategic outlook based

on financial, technological, and operational considerations,thus providing the foundation for making well-informed

business decisions Additionally, Part I is designed to allowyou to address high-level technical architecture interests.Part I includes the following chapters:

Chapter 1 , "Introduction to Wireless LAN

Technologies" This chapter will help you develop the

basic understanding of WLAN technology that is neededfor effectively using this book The OSI framework

illustrates how WLANs relate to other internetworkingtechnologies, including LAN, WAN, and mobile cellularsolutions The framework will also help position the

WLAN-specific concepts that are covered throughout theremainder of this chapter

Chapter 3 , "Preparation and Planning" This chapter

focuses on the preparation and planning considerationsthat are critical for successfully deploying your

enterprise WLAN Our aim is to provide a structuredapproach for your deployment, highlighting areas thatrequire preparatory work, as you need to identify

management and technical dependencies that are

unique to your context

Chapter 4 , "Supplementary and Complementary Services" This chapter covers supplementary services

and applications These include voice, video, guest

WLAN acess, and location-based services (LBS)

Complementary and supplementary services greatlyincrease the complexity of your network by adding

several incremental challenges This chapter outlinesthe benefits and challenges that are associated witheach enhanced service In addition, strategies to

identify the proper mix and implementation of theseservices are discussed to maximize the positive impactand success of the services

Part II, "Wireless LAN Architecture, Design, and

Deployment," addresses the key areas of architecting,

designing, and deploying an enterprise-class WLAN Most of

chapter also provides recommendations on how to

develop a successful architecture Finally, it clarifies themost important technical aspects of wireless LANs that

do not apply to traditional wired ones

Chapter 6 , "Wireless LAN Deployment

Considerations" This chapter discusses the

implementation considerations that are required whendeploying an enterprise-class WLAN Enterprise-classWLAN deployments are complex and lengthy processesthat include many interdependent factors

Methodologies and frameworks are provided that willhelp guide the WLAN deployment along the critical pathand minimize the execution risk associated with theprogram

Chapter 7 , "Security and Wireless LANs" This

chapter describes how to think securely in the context

of IT communications infrastructure Fundamental

security vulnerabilities are tackled, and methods areprovided for identifying security threats Security terms

Chapter 8 , "Management Strategies for Wireless LANs" This chapter introduces the fundamentals of

wireless network management, the unique challengesassociated with managing wireless networks, and thevarious strategies that can be adopted to support thiscritical area

Part III, "Wireless LAN Deployment Case Studies,"

provides real-world case studies of WLAN solutions

implemented by various enterprise-class institutions Thesestudies outline the requirements and constraints from theseinstitutions and reveal the recommended practices for each.Key hurdles and lessons learned from actual deploymentscomplement the ideals and theoretical notions outlined inthis book This part includes the following chapters:

Chapter 9 , "Enterprise Case Study" This chapter

provides a detailed case study of the global WLAN

deployment of Cisco Systems Inc The question for

Cisco IT was not whether WLANs should be deployed,because Cisco had long since identified the many

benefits offered by the technology, but rather how Ciscocould cost-effectively maintain control, reduce overallsupport costs, ensure that a secure wireless

infrastructure was used, and still provide benefits toCisco employees This chapter discusses why and howCisco pursued its enterprise-wide WLAN deployment

Chapter 10 , "Healthcare Case Study" This chapter

covers the strategic drivers of Lifespan's WLAN

Lifespan's business model is discussed, as is the

strategy that the organization employed for designing,implementing, and operating its WLAN solution

Chapter 11 , "Manufacturing Case Study" This

chapter discusses a deployment of a WLAN in a largeand successful manufacturing company The specificdemands and constraints that the manufacturing

industry imposes on WLANs are touched upon, as arethe strategies that the company employed to

accommodate these specific needs

Chapter 12 , "Education Case Study" This chapter

introduces an extremely successful deployment of

WLANs in the educational vertical Griffith University inQueensland, Australia, deployed a university-wide

WLAN to provide increased IT services, reduce the load

on existing computing labs, and supplement the

existing wired network infrastructure This chapter

covers the rationale for providing students and staffwith the mobility benefits offered by WLAN technologyand how the university executed its plan

Part IV, "Appedixes," includes the following:

Appendix A , "Wireless LAN Standards Reference"

This appendix provides summary descriptions of thevarious WLAN standards, including the infamous

"802.11 alphabet soup."

Appendix B , "Wireless LAN Security References"

This appendix provides descriptions and definitions ofthe many facets of WLAN security

Appendix C , "Example Project Plan for an

Enterprise-Class WLAN Deployment" This appendix

is composed of examples that have been proven to besuccessful in developing and deploying an enterprise-class WLAN

Finally, a glossary of terms is included for your convenience andreview

deployment project plan

Chapter 1 Introduction to Wireless LAN Technologies

Networks have become a pervasive element of everyday life.Even though they can adopt different physical characteristicsand carry diverse payloads, they all share a common set offundamental attributes The essence of a network is the factthat it connects or relates objects or devices

The instantiation of this connection can adopt many forms Itcan be intangible, as is the case in an organizational or

relational network, or it can be tangible Examples of tangiblenetworks include a highway system, an electrical grid, and datacommunications networks These types of networks are

designed and built to interconnect nodes so that objects can be

by means of a meshed infrastructure of roads The electricalgrid transports electrons between the power generating plantsand the points of consumption Finally, data communicationsnetworks carry informationthat is voice, video, or datafrom

respective sources to destinations The definitions of source anddestination are purposely left open because they include people

in addition to mechanical and electronic machines

The Business Case for Enterprise-Class Wireless LANs focuses

on a specific subset of data networks, namely wireless localarea networks (WLANs) As such, from here on you shall see

Information has become the engine of our society It forms thebasis of entire industries as in services, media, and advertising.Information provides a competitive advantage to other

industries such as financial services, manufacturing, and

transportation Government uses information to preempt andaddress security threats The entire educational system is basedupon information transfer to pupils Finally, information is a

means of relaxation and entertainment for many of us

Literature, music, television, and movies are in their most

abstract form sources of information As such, information'svalue and uses are tremendously varied and exceptionally wide

in scope

Over time, businesses and people have come to want and

expect accessibility to their source of information where they want it, when they want it, and how they want it The digital

revolution has brought us one step closer to this reality It notonly spawned an entire new industrythe information technologyindustrybut literally disrupted how society conducts business,functions, and entertains itself Many of us today are spendingour professional lives trying to leverage information and

technology to create new value propositions, capture

efficiencies and cost savings, and increase productivity

In his 1995 book Being Digital, Nicholas Negroponte, director of

the Massachusetts Institute of Technology's Media Laboratory,foresaw that the digital revolution would be a catalyst for a

digital flip.[1] Negroponte postulated that content that was

traditionally delivered via terrestrial channels would be flippedonto wireless channels An example is telephony At the sametime, content that was typically delivered via wireless channelswould be migrated onto terrestrial carriers For example,

television used to be delivered via radio or satellite Today,

information can be roughly categorized into two types:

Information we want access to anywhere and

anytime Cellular mobile voice communications is a prime

example Its explosive growth in terms of technologies andconsumer adoption rates supports the case of a large

demand for anywhere and anytime access to information

Information we consume in fixed locations An example

would be television Most of us do not watch television while

on the move We watch TV at home, in a hotel room, or in alounge We do not necessarily require mobility for televisionbecause we tend to associate it with relaxation and sittingdown

although somewhat unexpected, does stand to reason As such,you can make a valid distinction between applications that

demand mobility and those that do not or do so to a very lowdegree

In the same way that cellular technologies have extended thePlain Old Telephone Systems (POTS) beyond the boundaries ofthe wired infrastructure, WLANs extend data communicationsnetworks beyond traditional physical boundaries The

implications are vast and complex Management guru Dr

Clayton Christensen coined the term disruptive technology in his book The Innovator's Dilemma Christensen defined a

disruptive technology as a new technological innovation,

product, or service that eventually overturns the existing

dominant technology in the market This occurs despite the factthat the disruptive technology is both radically different fromthe leading technology and that it often initially performs worsethan the leading technology according to existing measures ofperformance A disruptive technology thus effectively comes todominate an existing market either by filling a role in a newmarket that the older technology could not fill or by

successively moving up-market through performance

improvements until finally displacing the market incumbents

Applying Christensen's definition, wireless networks are truly adisruptive technology They are fueling growth in companies,capturing efficiencies, boosting productivity, and causing entireindustries to rethink their business strategies.[2]

be moved through the ether to the point where it is required.There is no need for hardwiring There is also no need for line-of-site, a barrier for infrared communication technology As

such, WLANs provide an extendable, totally transparent meansfor interconnecting entities These entities can be personal

computers (PCs), personal digital assistants (PDAs), phones,sensors, radio frequency identification (RFID) tag transceivers,and many more In theory, any device that can house a radiotransmitter and the appropriate software is a candidate for

becoming a WLAN node Given the traits of transparency andthe ability to connect heterogeneous types of devices, it is

important to understand the strengths and limitations of WLANs

to correctly align business or personal goals and technologicalsolutions

The next section provides a baseline high-level technical

overview of WLANs We compare WLANs' positioning to othernetworking technologies and introduce WLAN components, theirinner workings, and operational implications Even though thischapter is comprehensive, it is not exhaustive and does notdescribe all the technical intricacies of WLAN technology

Let us start with the idea that complex problems are usuallybroken down into modular components to facilitate

understanding and to make the solution more tractable For this

purpose, data communications make use of the Open Systems

Interconnection (OSI) reference model Given the extensive

coverage of this model available in other books, this book doesnot intend to provide a complete and exhaustive overview ofthe OSI reference model Instead, this section provides a briefsummary of the model and focuses on the sections that aremost relevant within the context of this book

subtasks Within this framework, two types of communicationoccur:

Interface Layers communicate with their neighbors

through an interface A layer presents or receives

information from its respective adjacent layers in a

Protocol The second type of communication is with a peer

layer by means of a protocol Peer layers are at the same

level but in different nodes As such, network nodes cancommunicate directly on a layer-by-layer basis with othernetwork nodes However, the semantics of this

communication are restricted to each layer

The seven layers that make up the OSI reference model and thetwo communication types are illustrated in Figure 1-1

Figure 1-1 OSI Reference Model

Note

speeds, maximum transmission distances, voltage levels,

connectors, pin functions, conversion of information into

signals, and synchronization The physical characteristics thatare most important in the context of this book are the transportmedium, the topology, and the data encoding techniques Anoverview of each follows

Transport Medium

The transport medium defines the type and characteristics ofthe physical channel that carries information In its strictestsense, the channel is used as a tunnel for electricity or

electromagnetic waves For the purpose of this book, this

section makes the distinction between electrical, optical, andradio channels

electrons or electricity from source to destination An opticalchannel employs a fiber optic cable to guide light between theemitter and the receiver Finally, a radio frequency (RF) channelutilizes the radio band of the electromagnetic spectrum to carrysignals A key difference of RF is that the RF channel is not

bounded or confined to the actual physical systems but relies onthe free space of air

Indeed, RF is truly unbounded because the ether has no

borders Because RF signals are not guided by a conduit, theycan theoretically propagate in any direction This borderlesscharacteristic of RF has two important implications:

External influences have a greater impact on unboundedsignals and their properties because the lack of a conduitimplicitly prevents shielding from external influences

Radio communication is always a broadcast in the sensethat any device can tune into the signal

The broadcast nature of radio communication has importantimplications for both WLAN technology and applications Forexample, transmissions can inherently be intercepted by anynetwork-attached station When combined with nondirectionalantennas, every station intercepts every transmission of everyother station Not only does this have security implications, but

it also requires methods for resolving orderly access to the air.These implications will be covered in greater detail in Chapter 7,

"Security and Wireless LANs."

Topology

The following list describes the four basic topologies for

networks consisting of three or more nodes:

distinction must be made between the physical appearance of astar topology and the logical layout and behavior as a bus

Figure 1-3 Attenuation of a Radio Signal