Part I Voice over IP 3
Chapter 1 Cisco VoIP Implementations 5
"Do I Know This Already?" Quiz 5
Foundation Topics 10
Introduction to VoIP Networks 10
Benefits of Packet Telephony Networks 10
Packet Telephony Components 11
Analog Interfaces 13
Digital Interfaces 14
Stages of a Phone Call 15
Distributed Versus Centralized Call Control 16
Digitizing and Packetizing Voice 19
Basic Voice Encoding: Converting Analog to Digital 19
Basic Voice Encoding: Converting Digital to Analog 20
The Nyquist Theorem 21
Quantization 22
Compression Bandwidth Requirements and Their Comparative Qualities 24
Digital Signal Processors 25
Encapsulating Voice Packets 27
End-to-End Delivery of Voice 27
Protocols Used in Voice Encapsulation 30
Reducing Header Overhead 32
Bandwidth Calculation 34
Impact of Voice Samples and Packet Size on Bandwidth 34
Data Link Overhead 37
Security and Tunneling Overhead 37
Calculating the Total Bandwidth for a VoIP Call 39
Effects of VAD on Bandwidth 41
Implementing VoIP Support in an Enterprise Network 42
Enterprise Voice Implementations 42
Voice Gateway Functions on a Cisco Router 44
Cisco Unified CallManager Functions 45
Enterprise IP Telephony Deployment Models 46
Single-Site Model 46
Multisite with Centralized Call Processing Model 46
Multisite with Distributed Call Processing Model 47
Clustering over WAN Model 48
Identifying Voice Commands in IOS Configurations 48
Call Admission Control (CAC) 49
Part II Quality of Service 55
Chapter 2 IP Quality of Service 57
"Do I Know This Already?" Quiz 57
Foundation Topics 62
Introduction to QoS 62
Converged Network Issues Related to QoS 62
Available Bandwidth 63
End-to-End Delay 64
Delay Variation 65
Packet Loss 66
Definition of QoS and the Three Steps to Implementing It 68
Implementing QoS 69
Identifying and Comparing QoS Models 72
Best-Effort Model 72
Integrated Services Model 73
Differentiated Services Model 74
QoS Implementation Methods 76
Legacy Command-Line Interface (CLI) 76
Modular QoS Command-Line Interface (MQC) 76
AutoQoS 79
Router and Security Device Manager (SDM) QoS Wizard 81
Foundation Summary 89
Q&A 91
Chapter 3 Classification, Marking, and NBAR 93
"Do I Know This Already?" Quiz 93
Foundation Topics 97
Classification and Marking 97
Layer 2 QoS: CoS on 802.1Q/P Ethernet Frame 98
Layer 2 QoS: DE and CLP on Frame Relay and ATM (Cells) 99
Layer 2 1/2 QoS: MPLS EXP Field 100
The DiffServ Model, Differentiated Services Code Point (DSCP), and Per-Hop Behavior
(PHB) 100
IP Precedence and DSCP 102
QoS Service Class 106
Trust Boundaries 108
Network Based Application Recognition (NBAR) 110
Cisco IOS Commands to Configure NBAR 112
Foundation Summary 118
Q&A 119
Chapter 4 Congestion Management and Queuing 123
"Do I Know This Already?" Quiz 123
Foundation Topics 127
Introduction to Congestion Management and Queuing 127
First-In-First-Out, Priority Queuing, Round-Robin, and Weighted Round-Robin Queuing 130
Weighted Fair Queuing 132
WFQ Classification and Scheduling 133
WFQ Insertion and Drop Policy 135
Benefits and Drawbacks of WFQ 135
Configuring and Monitoring WFQ 135
Class-Based Weighted Fair Queuing 138
Classification, Scheduling, and Bandwidth Guarantee 139
Benefits and Drawbacks of CBWFQ 140
Configuring and Monitoring CBWFQ 141
Low-Latency Queuing 142
Benefits of LLQ 144
Configuring and Monitoring LLQ 144
Foundation Summary 146
Q&A 147
Chapter 5 Congestion Avoidance, Policing, Shaping, and Link
Efficiency Mechanisms 149
"Do I Know This Already?" Quiz 149
Foundation Topics 153
Congestion Avoidance 153
Tail Drop and Its Limitations 153
Random Early Detection 154
Weighted Random Early Detection 156
Class-Based Weighted Random Early Detection 158
Configuring CBWRED 158
Traffic Shaping and Policing 163
Measuring Traffic Rates 165
Cisco IOS Policing and Shaping Mechanisms 167
Link Efficiency Mechanisms 167
Layer 2 Payload Compression 168
Header Compression 169
Link Fragmentation and Interleaving 171
Applying Link Efficiency Mechanisms 171
Foundation Summary 172
Q&A 175
Chapter 6 Implementing QoS Pre-Classify and Deploying End-to-End QoS 177
"Do I Know This Already?" Quiz 177
Foundation Topics 180
Implementing QoS Pre-Classify 180
Virtual Private Networks (VPN) 180
QoS Pre-Classify Applications 181
QoS Pre-Classification Deployment Options 183
Deploying End-to-End QoS 185
QoS Service Level Agreements (SLAs) 186
Enterprise Campus QoS Implementations 188
WAN Edge QoS Implementations 190
Control Plane Policing (CoPP) 192
Foundation Summary 194
Q&A 198
Chapter 7 Implementing AutoQoS 201
"Do I Know This Already?" Quiz 201
Foundation Topics 205
Introducing AutoQoS 205
Implementing and Verifying AutoQoS 207
Two-Step Deployment of AutoQoS Enterprise on Routers 209
Deploying AutoQoS VoIP on IOS-Based Catalyst Switches 210
Verifying AutoQoS on Cisco Routers and IOS-Based Catalyst Switches 212
AutoQoS Shortcomings and Remedies 215
Automation with Cisco AutoQoS 215
Common AutoQoS Problems 218
Interpreting and Modifying AutoQoS Configurations 219
Foundation Summary 222
Q&A 227
Part III Wireless LAN 229
Chapter 8 Wireless LAN QoS Implementation 231
"Do I Know This Already?" Quiz 231
Foundation Topics 235
The Need for Wireless LAN QoS 235
WLAN QoS Description 237
Split MAC Architecture and Light Weight Access Point 238
Current Wireless LAN QoS Implementation 239
Configuring Wireless LAN QoS 243
Foundation Summary 247
Q&A 252
Chapter 9 Introducing 802.1x and Configuring Encryption and Authentication
on Lightweight Access Points 255
"Do I Know This Already?" Quiz 255
Foundation Topics 258
Overview of WLAN Security 258
WLAN Security Issues 258
Evolution of WLAN Security Solutions 259
802.1x and EAP Authentication Protocols 260
EAP Authentication Protocols 262
Cisco LEAP 262
EAP-FAST 264
EAP-TLS 266
PEAP 267
WPA, 802.11i, and WPA2 269
Configuring Encryption and Authentication on Lightweight Access Points 272
Open Authentication 272
Static WEP Authentication 273
WPA Preshared Key 274
Web Authentication 276
802.1x Authentication 278
Foundation Summary 281
Q&A 285
Chapter 10 WLAN Management 287
"Do I Know This Already?" Quiz 287
Foundation Topics 291
The Need for WLAN Management 291
Cisco Unified Wireless Networks 291
Cisco WLAN Implementation 292
WLAN Components 294
CiscoWorks Wireless LAN Solution Engine 295
WLSE Software Features 295
WLSE Key Benefits 296
CiscoWorks WLSE and WLSE Express 296
Simplified WLSE Express Setup 297
WLSE Configuration Templates 298
WLSE IDS Features 298
WLSE Summary 298
Cisco Wireless Control System 299
WCS Location Tracking Options 300
WCS Base Software Features 300
WCS Location Software Features 301
WCS Location + 2700 Series Wireless Location Appliance Features 301
WCS System Features 301
Cisco WCS User Interface 302
Cisco WCS System Requirements 302
WCS Summary Pages 303
Wireless Location Appliance 304
Wireless Location Appliance Architecture 305
Wireless Location Appliance Applications 305
WCS Configuration Examples 306
WCS Login Steps 306
Changing the Root Password 306
Adding a Wireless LAN Controller 307
Configuring Access Points 308
WCS Map 309
Adding a Campus Map 309
Adding a New Building 310
Rogue Access Point Detection 312
Rogue Access Point Alarms 312
Rogue Access Point Location 313
Foundation Summary 314
Q&A 317
Part IV Appendix 319
Appendix A Answers to the "Do I Know This Already?" Quizzes and Q&A Sections 321
