Vendor-neutral wireless network training and certification Objective-by-Objective coverage of the CWNA certification exam Certified Wireless Network Administrator TM Official Study Guide Exam PW0-100 Planet3 Wireless cwna TM Industry Approved! Endorsed by the Wireless LAN Association CWNP™ Certification Program The Certified Wireless Network Professional Training & Certification Program is intended for individuals who administer, install, design, and support IEEE 802.11 compliant wireless networks. Because the CWNP program is vendor neutral, candidates who achieve the different levels of CWNP Certification will be trained and qualified to administer and support many different brands of wireless LAN hardware. Although there are many manufacturers of wireless LAN hardware, the technologies behind the hardware – Radio Frequency and Local Area Networking – are the same for each piece of gear. Each manufacturer approaches these technologies in different ways. The CWNP program consists of 4 levels of certification: Administrator – Site survey, installation and management of 802.11 compliant wireless LANs Security Expert – Design and implementation of 802.11 security techniques, processes, hardware, and software Integrator – Advanced site survey, design, bridging and integration of 802.11 compliant wireless LANs Engineer – Lab intensive approach to design, implementation, troubleshooting & repair, security and integration of 802.11 compliant wireless LANs CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. Copyright © 2002 Planet3 Wireless, Inc., P.O. Box 412, Bremen Georgia 30110. World rights reserved. No part of this publication may be stored in any retrieval system, transmitted, or reproduced in any way, including but not limited to photocopying, photographing, magnetic, electronic, or other record, without the prior written agreement and written permission of Planet3 Wireless, Inc. ISBN: 0-9716057-2-6 Version: FAY534IR8E1 CNWP, CWNA, CWNI, CWSE, CWNE, CWAP, CWEC and their respective logos are registered marks of Planet3 Wireless, Inc. in the United States and/or other countries. This study guide and reference manual are not sponsored by or affiliated with any wireless LAN manufacturer, including those mentioned in the text and in the lab exercise notes. TRADEMARKS: Planet3 Wireless, Inc. has attempted throughout this book to distinguish proprietary trademarks from descriptive terms by following the capitalization style used by the manufacturers. The author and publisher have made their best efforts to prepare this book, and the content is based upon final release software whenever possible. Portions of the manuscript may be based on pre-release versions supplied by software manufactures. 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We at Planet3 Wireless would like to dedicate this book to our Lord Jesus Christ. It is through Him that we have had the talent, time, encouragement, and strength to work many long months in preparing this text. Our goal through the creation of this book and through all things that He allows us to do going forward is to glorify Him. We acknowledge His hand in every part of our company, our work, and our friendships. We would also like to thank our families who have been amazingly supportive, our friends who have encouraged us and everyone that contributed to this book in any way. “I can do all things through Christ, who strengthens me.” – Philippians 4:13 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. Acknowledgements  Devin Akin  Kevin Sandlin  Scott Turner  Robert Nicholas  Josh McCord  Jeff Jones  Stan Brooks  Bill Waldo  Barry Oxford Planet3 Wireless, Inc. would like to acknowledge and thank the following people for their tireless contributions to this work: Devin Akin, whose knowledge of wireless LANs, networking, and radio frequency surprised even us. His talents to convey, teach, write, and edit were essential in making this the most accurate and comprehensive writing on wireless LANs in today's market. Scott Turner, who constantly keeps us in line and focused on what is important. Scott's work in formatting, framing, content organization, and graphics creation was indispensable. Scott's eye for detail and his motivation for perfection in everything he does keep us in awe. Kevin Sandlin, for his intellect to make difficult concepts sound simple, his skill to write and edit the most difficult material, and his ability to motivate every member of the team to do their best and to keep their eyes on the sometimes moving target. His leadership skills are second to none. Robert Nicholas, for his ability to conceptualize and create difficult graphics and radio frequency concepts, his savvy in presentation of difficult material, and his ability to find the answer to even the most vague concepts through diligent research and study. His effort in support of this book is greatly appreciated. Jeff Jones and Josh McCord, who have been with Planet3 since the beginning of this project. Their willingness to volunteer as much time and effort as was needed to make all of it possible has been amazing. They have been an inspiration to the entire team. Their relentless pursuit of perfection in support of Planet3's mission is recognized and greatly appreciated. Stan Brooks, Bill Waldo, and Barry Oxford, each of whom brought a unique set of skills to the review and quality assurance process for this publication. Their time, effort and eye for necessary changes were immeasurable, and helped to publish this book in a timely manner. CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. vi Contents Contents at a Glance Introduction xvi Chapter 1 Introduction to Wireless LANs 1 Chapter 2 Radio Frequency (RF) Fundamentals 17 Chapter 3 Spread Spectrum Technology 45 Chapter 4 Wireless LAN Infrastructure Devices 71 Chapter 5 Antennas and Accessories 103 Chapter 6 Wireless LAN Organizations and Standards 145 Chapter 7 802.11 Network Architecture 167 Chapter 8 MAC and Physical Layers 201 Chapter 9 Troubleshooting Wireless LAN Installations 223 Chapter 10 Wireless LAN Security 259 Chapter 11 Site Survey Fundamentals 295 Appendix A RF in Perspective 341 Glossary 347 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. Contents vii Contents Introduction xxiv Chapter 1 Chapter 2 Chapter 3 Introduction to Wireless LANs 1 The Wireless LAN Market 2 Today’s Wireless LAN Standards 3 Applications of Wireless LANs 3 Access Role 4 Network Extension 5 Building-to-Building Connectivity 5 Last Mile Data Delivery 6 Mobility 7 Small Office-Home Office 8 Summary 10 Key Terms 11 Review Questions 12 Answers to Review Questions 15 Radio Frequency (RF) Fundamentals 17 Radio Frequency 18 RF Behaviors 19 Gain 19 Loss 19 Reflection 20 Refraction 21 Diffraction 22 Scattering 23 Voltage Standing Wave Ratio (VSWR) 23 VSWR Measurements 24 Effects of VSWR 24 Solutions to VSWR 25 Principles of Antennas 25 Line of Sight (LOS) 25 Fresnel Zone 26 Obstructions 27 Antenna Gain 27 Intentional Radiator 27 Equivalent Isotropically Radiated Power (EIRP) 28 Radio Frequency Mathematics 29 Units of Measure 30 Watts (W) 30 Milliwatt 30 Decibels 30 dBm 32 dBi 34 Accurate Measurements 35 Key Terms 37 Review Questions 38 Answers to Review Questions 43 Spread Spectrum Technology 45 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. viii Contents Introducing Spread Spectrum 46 Chapter 4 Narrow Band Transmission 46 Spread Spectrum Technology 47 Uses of Spread Spectrum 48 Wireless Local Area Networks 48 Wireless Personal Area Networks 49 Wireless Metropolitan Area Networks 49 FCC Specifications 49 Frequency Hopping Spread Spectrum (FHSS) 50 How FHSS Works 50 Effects of Narrow Band Interference 51 Frequency Hopping Systems 51 Channels 51 Dwell Time 52 Hop Time 53 Dwell Time Limits 53 FCC Rules affecting FHSS 54 Direct Sequence Spread Spectrum (DSSS) 55 How DSSS Works 55 Direct Sequence Systems 55 Channels 56 Effects of Narrow Band Interference 58 FCC Rules affecting DSSS 58 Comparing FHSS and DSSS 58 Narrowband Interference 58 Cost 59 Co-location 59 Equipment compatibility and availability 60 Data rate & throughput 60 Security 61 Standards Support 61 Key Terms 62 Review Questions 63 Answers to Review Questions 68 Wireless LAN Infrastructure Devices 71 Access Points 72 Access Point Modes 73 Root Mode 74 Bridge Mode 74 Repeater Mode 75 Common Options 76 Fixed or Detachable Antennas 76 Advanced Filtering Capabilities 76 Removable (Modular) Radio Cards 77 Variable Output Power 77 Varied Types of Wired Connectivity 77 Configuration and Management 78 Wireless Bridges 79 Wireless Bridge Modes 80 Root Mode 80 Non-root Mode 81 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. Contents ix Access Point Mode 81 Chapter 5 Repeater Mode 81 Common Options 82 Fixed or Detachable Antennas 82 Advanced Filtering Capabilities 83 Removable (Modular) Radio Cards 83 Variable Output Power 83 Varied Types of Wired Connectivity 83 Configuration and Management 84 Wireless Workgroup Bridges 84 Common Options 85 Configuration and Management 85 Wireless LAN Client Devices 86 PCMCIA & Compact Flash Cards 86 Wireless Ethernet & Serial Converters 87 USB Adapters 88 PCI & ISA Adapters 88 Configuration and Management 89 Driver Installation 89 Manufacturer Utilities 89 Wireless Residential Gateways 90 Common Options 91 Configuration and Management 92 Enterprise Wireless Gateways 92 Configuration and Management 94 Key Terms 95 Review Questions 96 Answers to Review Questions 100 Antennas and Accessories 103 RF Antennas 105 Omni-directional (Dipole) Antennas 105 Usage 107 Semi-directional Antennas 108 Usage 109 Highly-directional Antennas 110 Usage 110 RF Antenna Concepts 111 Polarization 111 Gain 113 Beamwidth 113 Free Space Path Loss 114 The 6dB Rule 115 Antenna Installation 115 Placement 115 Mounting 116 Appropriate Use 116 Orientation 116 Alignment 117 Safety 117 Maintenance 118 Power over Ethernet (PoE) Devices 118 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. [...]... Independent Basic Service Set 16 8 16 8 16 8 16 9 16 9 16 9 16 9 16 9 16 9 17 1 17 1 17 2 17 2 17 2 17 3 17 3 17 3 17 4 17 4 17 5 17 6 17 6 17 7 18 1 18 1 18 2 18 2 18 3 18 4 18 5 18 5 18 6 18 7 18 9 19 0 19 0 19 1 19 1 19 2 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc xii Contents Key Terms Review Questions Answers to Review Questions 19 4 19 5 19 9 Chapter 8 MAC and Physical Layers 2 01 How Wireless LANs Communicate Wireless LAN Frames... of Electrical and Electronics Engineers IEEE 802 .11 IEEE 802 .11 b IEEE 802 .11 a IEEE 802 .11 g Major Organizations Wireless Ethernet Compatibility Alliance 14 6 14 6 14 7 14 7 14 8 14 8 14 8 14 8 14 9 14 9 14 9 14 9 14 9 15 0 15 1 15 2 15 2 15 3 15 3 15 4 15 4 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc Contents xi European Telecommunications Standards Institute Wireless LAN Association Competing Technologies HomeRF... Connector RF Cables RF “Pigtail” Adapter Cable Key Terms Review Questions Answers to Review Questions Chapter 6 11 9 12 0 12 0 12 1 12 1 12 1 12 2 12 2 12 2 12 3 12 3 12 4 12 5 12 5 12 6 12 7 12 7 12 8 13 0 13 0 13 1 13 3 13 4 13 4 13 6 13 7 13 8 14 2 Wireless LAN Organizations and Standards 14 5 14 5 Federal Communications Commission ISM and UNII Bands Advantages and Disadvantages of License-Free Bands Industrial Scientific Medical... Placement Spot Checks Site Survey Reporting Report Format Purpose and Business Requirements Methodology 296 297 298 299 3 01 302 303 305 306 307 307 308 308 309 311 311 312 312 313 314 316 316 317 317 318 319 3 21 3 21 322 322 325 326 327 327 327 328 328 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc Contents xv RF Coverage Areas Throughput Interference Problem Areas Drawings Hardware placement & configuration... Wireless LAN Association Competing Technologies HomeRF Bluetooth Infrared Data Association (IrDA) Infrared Wireless LAN Interoperability Forum (WLIF) Key Terms Review Questions Answers to Review Questions Chapter 7 15 4 15 5 15 5 15 6 15 6 15 7 15 7 15 8 15 9 16 0 16 4 802 .11 Network Architecture 16 7 Locating a Wireless LAN Service Set Identifier Beacons Time Synchronization FH or DS Parameter Sets SSID Information... Radiator EIRP Wave propagation 1. 2 RF Math 1. 2 .1 Understand and apply the basic components of RF mathematics Watt Milliwatt CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc Introduction xxi Decibel (dB) dBm dBi 1. 3 Spread Spectrum Technologies 1. 3 .1 Identify some of the different uses for spread spectrum technologies Wireless LANs Wireless PANs Wireless WANs 1. 3.2 Comprehend the differences... networks 4.3.3 Identify how and where the following security precautions are used to secure a wireless LAN WEP Cell sizing Monitoring User authentication Wireless DMZ CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc xxvi Introduction Wireless LAN Industry and Standards – 13 % 5 .1 Standards 5 .1. 1 Identify, apply and comprehend the differences between the following wireless LAN standards 802 .11 ... information below to contact Planet3 Wireless, Inc Planet3 Wireless, Inc P.O Box 412 Bremen, Georgia 3 011 0 866-GET-CWNE http://www.p 3wireless. com http://www.cwne.com Direct feedback via email: feedback@cwne.com CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc CHAPTER Introduction to Wireless LANs 1 CWNA Exam Objectives Covered: Identify the technology roles for which wireless LAN technology is an... by the Wireless Ethernet Compatibility Alliance, or WECA IEEE 802 .11 a - describes much faster data transfer rate than (but lacks backwards compatibility with) IEEE 802 .11 b, and uses the 5 GHz UNII frequency bands IEEE 802 .11 g - the most recent draft based on the 802 .11 standard that describes data transfer rates equally as fast as IEEE 802 .11 a, and boasts the backward compatibility to 802 .11 b required... Graphical documentation Recommendations CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc Introduction xxv Wireless LAN Security – 16 % 4 .1 Protection 4 .1. 1 Identify the strengths, weaknesses and appropriate uses of the following wireless LAN security techniques WEP AES Filtering Emerging security techniques 4.2 Attacks 4.2 .1 Describe the following types of wireless LAN security attacks, and explain . Concepts 11 1 Polarization 11 1 Gain 11 3 Beamwidth 11 3 Free Space Path Loss 11 4 The 6dB Rule 11 5 Antenna Installation 11 5 Placement 11 5 Mounting 11 6 Appropriate Use 11 6 Orientation 11 6 Alignment. 802 .11 15 2 IEEE 802 .11 b 15 2 IEEE 802 .11 a 15 3 IEEE 802 .11 g 15 3 Major Organizations 15 4 Wireless Ethernet Compatibility Alliance 15 4 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. . 11 6 Alignment 11 7 Safety 11 7 Maintenance 11 8 Power over Ethernet (PoE) Devices 11 8 CWNA Study Guide © Copyright 2002 Planet3 Wireless, Inc. x Contents Common PoE Options 11 9