Foreword xx
Introduction xxi
Chapter 1 Identifying Issues in a Multisite Deployment 3
Chapter Objectives 3
Multisite Deployment Challenge Overview 3
Quality Challenges 5
Bandwidth Challenges 6
Availability Challenges 8
Dial Plan Challenges 9
Overlapping and Nonconsecutive Numbers 12
Fixed Versus Variable-Length Numbering Plans 13
Variable-Length Numbering, E.164 Addressing, and DID 15
Optimized Call Routing and PSTN Backup 15
NAT and Security Issues 17
Chapter Summary 18
References 19
Review Questions 19
Chapter 2 Identifying Multisite Deployment Solutions 23
Chapter Objectives 23
Multisite Deployment Solution Overview 24
Quality of Service 24
QoS Advantages 25
Solutions to Bandwidth Limitations 26
Low-Bandwidth Codecs and RTP-Header Compression 28
Codec Configuration in CUCM 29
Disabled Annunciator 29
Local Versus Remote Conference Bridges 30
Mixed Conference Bridge 30
Transcoders 31
Multicast MOH from the Branch Router Flash 33
Availability 37
PSTN Backup 38
MGCP Fallback 39
Fallback for IP Phones 40
Using CFUR During WAN Failure 42
Using CFUR to Reach Users on Cell Phones 42
AAR and CFNB 43
Mobility Solutions 44
Dial Plan Solutions 44
Dial Plan Components in Multisite Deployments 45
NAT and Security Solutions 46
Cisco Unified Border Element in Flow-Through Mode 46
Summary 48
References 48
Review Questions 48
Chapter 3 Implementing Multisite Connections 53
Chapter Objectives 53
Examining Multisite Connection Options 54
MGCP Gateway Characteristics 55
H.323 Gateway Characteristics 55
SIP Trunk Characteristics 56
H.323 Trunk Overview 56
H.323 Trunk Comparison 57
MGCP Gateway Implementation 59
H.323 Gateway Implementation 61
Cisco IOS H.323 Gateway Configuration 63
CUCM H.323 Gateway Configuration 64
Trunk Implementation Overview 65
Gatekeeper-Controlled ICT and H.225 Trunk Configuration 66
Implementing SIP Trunks 67
Implementing Intercluster and H.225 Trunks 69
CUCM Gatekeeper-Controlled ICT and H.225 Trunk Configuration 70
Summary 73
References 73
Review Questions 74
Chapter 4 Implementing a Dial Plan for Multisite Deployments 79
Chapter Objectives 79
Multisite Dial Plan Overview 79
Implementing Access and Site Codes 80
Implementing Site Codes for On-Net Calls 80
Digit-Manipulation Requirements When Using Access and Site Codes 80
Access and Site Code Requirements for Centralized Call-
Processing Deployments 82
Implementing PSTN Access 83
Transformation of Incoming Calls Using ISDN TON 84
Implementing Selective PSTN Breakout 86
Configure IP Phones to Use Remote Gateways for Backup PSTN Access 87
Considerations When Using Backup PSTN Gateways 88
Implementing PSTN Backup for On-Net Intersite Calls 89
Digit-Manipulation Requirements for PSTN Backup of On-Net Intersite Calls 89
Implementing Tail-End Hop-Off 91
Considerations When Using TEHO 92
Summary 92
Review Questions 93
Chapter 5 Examining Remote-Site Redundancy Options 97
Chapter Objectives 97
Remote-Site Redundancy Overview 98
Remote-Site Redundancy Technologies 99
Basic Cisco Unified SRST Usage 101
Cisco Unified SIP SRST Usage 101
CUCME in SRST Mode Usage 102
Cisco Unified SRST Operation 102
SRST Function of Switchover Signaling 103
SRST Function of the Call Flow After Switchover 104
SRST Function of Switchback 105
SRST Timing 105
MGCP Fallback Usage 107
MGCP Fallback Operation 107
MGCP Gateway Fallback During Switchover 108
MGCP Gateway Fallback During Switchback 109
MGCP Gateway Fallback Process 110
Cisco Unified SRST Versions and Feature Support 112
SRST 4.0 Platform Density 112
Dial Plan Requirements for MGCP Fallback and SRST Scenarios 113
Ensuring Connectivity for Remote Sites 114
Ensuring Connectivity from the Main Site Using Call Forward Unregistered 115
CFUR Considerations 115
Keeping Calling Privileges Active in SRST Mode 117
SRST Dial Plan Example 117
Summary 118
References 119
Review Questions 119
Chapter 6 Implementing Cisco Unified SRST and MGCP Fallback 123
Chapter Objectives 123
MGCP Fallback and SRST Configuration 124
Configuration Requirements for MGCP Fallback and Cisco Unified SRST 124
Cisco Unified SRST Configuration in CUCM 125
SRST Reference Definition 125
CUCM Device Pool 126
SRST Configuration on the Cisco IOS Gateway 126
SRST Activation Commands 127
SRST Phone Definition Commands 127
SRST Performance Commands 128
Cisco Unified SRST Configuration Example 129
MGCP-Gateway-Fallback Configuration on the Cisco IOS Gateway 130
MGCP Fallback Activation Commands 131
MGCP Fallback Configuration Example 131
Dial Plan Configuration for SRST Support in CUCM 132
SRST Dial Plan of CFUR and CSS 133
SRST Dial Plan: Max Forward UnRegistered Hops to DN 134
MGCP Fallback and SRST Dial Plan Configuration in the Cisco IOS Gateway 135
SRST Dial Plan Components for Normal Mode Analogy 135
SRST Dial Plan Dial Peer Commands 136
SRST Dial Plan Commands: Open Numbering Plans 140
SRST Dial Plan Voice Translation-Profile Commands for Digit Manipulation 142
SRST Dial Plan Voice Translation-Rule Commands for
Number Modification 143
SRST Dial Plan Profile Activation Commands for Number Modification 144
SRST Dial Plan Class of Restriction Commands 145
SRST Dial Plan Example 146
Telephony Features Supported by Cisco Unified SRST 150
Special Requirements for Voice-Mail Integration Using Analog Interfaces 151
Summary 152
References 152
Review Questions 152
Chapter 7 Implementing Cisco Unified Communications Manager Express in
SRST Mode 157
Chapter Objectives 157
CUCME Overview 158
CUCME in SRST Mode 158
Standalone CUCME Versus CUCM and CUCME in SRST Mode 159
CUCME Features 161
CUCME Features and Versions 161
Other CUCME Features 162
General Configuration of CUCME 163
CUCME Basic Configuration 164
CUCME Configuration Providing Phone Loads 165
CUCME Configuration for Music On Hold 165
Configuring CUCME in SRST Mode 167
Phone-Provisioning Options 168
Advantages of CUCME SRST 169
Phone Registration Process 169
Configuring CUCME for SRST 170
CUCME for SRST Mode Configuration 172
Summary 173
References 173
Review Questions 173
Chapter 8 Implementing Bandwidth Management 177
Chapter Objectives 177
Bandwidth Management Overview 177
CUCM Codec Configuration 178
Review of CUCM Codecs 179
Local Conference Bridge Implementation 181
Transcoder Implementation 184
Implementing a Transcoder at the Main Site 185
Configuration Procedure for Implementing Transcoders 187
Multicast MOH from Branch Router Flash Implementation 191
Implementing Multicast MOH from Branch Router Flash 192
Configuration Procedure for Implementing Multicast MOH from Branch Router
Flash 194
Summary 202
References 203
Review Questions 203
Chapter 9 Implementing Call Admission Control 207
Chapter Objectives 207
Call Admission Control Overview 208
Call Admission Control in CUCM 208
Locations 209
Locations: Hub-and-Spoke Topology 210
Locations: Full-Mesh Topology 211
Configuration Procedure for Implementing Locations-Based CAC 212
Locations Configuration Example of a Hub-and-Spoke Topology 212
RSVP-Enabled Locations 215
Three Call Legs with RSVP-Enabled Locations 215
Characteristics of Phone-to-RSVP Agent Call Legs 216
Characteristics of RSVP Agent-to-RSVP Agent Call Legs 217
RSVP Basic Operation 217
RSVP-Enabled Location Configuration 220
Configuration Procedure for Implementing RSVP-Enabled Locations-Based
CAC 221
Step 1: Configure RSVP Service Parameters 221
Step 2: Configure RSVP Agents in Cisco IOS Software 225
Step 3: Add RSVP Agents to CUCM 227
Step 4: Enable RSVP Between Location Pairs 228
Automated Alternate Routing 230
Automated Alternate Routing Characteristics 231
AAR Example 231
AAR Considerations 233
AAR Configuration Procedure 234
H.323 Gatekeeper CAC 239
H.323 Gatekeeper Used for Call Routing for Address Resolution Only 240
Using an H.323 Gatekeeper for CAC 243
H.323 Gatekeeper Also Used for Call Admission Control 245
Provide PSTN Backup for Calls Rejected by CAC 247
Configuration Procedure for Implementing H.323 Gatekeeper-Controlled Trunks
with CAC 248
Summary 249
References 249
Review Questions 250
Chapter 10 Implementing Call Applications on Cisco IOS Gateways 255
Chapter Objectives 255
Call Applications Overview 256
Tcl Scripting Language 256
VoiceXML Markup Language 257
The Analogy Between HTML and VoiceXML 258
Advantages of VoiceXML 259
Cisco IOS Call Application Support 259
Tcl Versus VoiceXML Features in Cisco IOS 260
Cisco IOS Call Application Support Requirements 261
Examples of Cisco IOS Call Applications Available for
Download at Cisco.com 262
Call Application Auto-Attendant Script Example 263
Remote-Site Gateway Using an Auto-Attendant Script
During a WAN Failure 265
Auto-Attendant Tcl Script Flowchart 266
Call Application Configuration 267
Step 1: Download the Application from Cisco.com 268
Step 2: Upload and Uncompress the Script to Flash 268
Step 3a: Configure the Call Application Service Definition 269
Step 3b: Configure the Call Application Service Parameters 269
Step 4: Associate the Call Application with a Dial Peer 270
Call Application Configuration Example 270
Summary 272
References 272
Review Questions 272
Chapter 11 Implementing Device Mobility 277
Chapter Objectives 277
Issues with Devices Roaming Between Sites 277
Issues with Roaming Devices 278
Device Mobility Solves Issues of Roaming Devices 279
Device Mobility Overview 280
Dynamic Device Mobility Phone Configuration Parameters 280
Device Mobility Dynamic Configuration by Location-Dependent
Device Pools 282
Device Mobility Configuration Elements 283
The Relationship Between Device Mobility Configuration Elements 284
Device Mobility Operation 285
Device Mobility Operation Flowchart 286
Device Mobility Considerations 289
Review of Line and Device CSSs 289
Device Mobility and CSSs 290
Examples of Different Call-Routing Paths Based on Device Mobility Groups and
TEHO 290
Device Mobility Configuration 293
Steps 1 and 2: Configure Physical Locations and Device Mobility Groups 293
Step 3: Configure Device Pools 293
Step 4: Configure Device Mobility Infos 294
Step 5a: Set the Device Mobility Mode CCM Service Parameter 295
Step 5b: Set the Device Mobility Mode for Individual Phones 296
Summary 297
References 297
Review Questions 297
Chapter 12 Implementing Extension Mobility 301
Chapter Objectives 301
Issues with Users Roaming Between Sites 301
Issues with Roaming Users 302
Extension Mobility Solves Issues of Roaming Users 303
CUCM Extension Mobility Overview 303
Extension Mobility: Dynamic Phone Configuration Parameters 304
Extension Mobility with Dynamic Phone Configuration by Device Profiles 305
CUCM Extension Mobility Configuration Elements 306
The Relationship Between Extension Mobility Configuration Elements 307
CUCM Extension Mobility Operation 308
Issues in Environments with Different Phone Models 310
Extension Mobility Solution to Phone Model Differences 310
Extension Mobility and Calling Search Spaces (CSS) 311
Alternatives to Mismatching Phone Models and CSS Implementations 312
CUCM Extension Mobility Configuration 313
Step 1: Activate the Cisco Extension Mobility Feature Service 313
Step 2: Set Cisco Extension Mobility Service Parameters 314
Step 3: Add the Cisco Extension Mobility Phone Service 315
Step 4: Create Default Device Profiles 315
Step 5a: Create Device Profiles 316
Step 5b: Subscribe the Device Profile to the Extension Mobility Phone
Service 316
Step 6: Associate Users with Device Profiles 318
Step 7a: Configure Phones for Cisco Extension Mobility 318
Step 7b: Subscribe the Phone to the Extension Mobility Phone Service 320
Summary 320
References 321
Review Questions 321
Chapter 13 Implementing Cisco Unified Mobility 327
Chapter Objectives 327
Cisco Unified Mobility Overview 327
Mobile Connect and Mobile Voice Access Characteristics 328
Cisco Unified Mobility Features 329
Cisco Unified Mobility Call Flow 330
Mobile Connect Call Flow of Internal Calls Placed from a Remote Phone 330
Mobile Voice Access Call Flow 331
Cisco Unified Mobility Components 332
Cisco Unified Mobility Configuration Elements 333
Shared Line Between the Phone and the Remote Destination Profile 335
Relationship Between Cisco Unified Mobility Configuration Elements 336
Cisco Unified Mobility Configuration 338
Configuring Mobile Connect 338
Configuring Mobile Voice Access 348
Summary 355
References 355
Review Questions 355
Chapter 14 Understanding Cryptographic Fundamentals and PKI 359
Chapter Objectives 359
Cryptographic Services 359
Symmetric Versus Asymmetric Encryption 362
Algorithm Example: AES 363
Asymmetric Encryption 364
Algorithm Example: RSA 365
Two Ways to Use Asymmetric Encryption 366
Hash-Based Message Authentication Codes 366
Algorithm Example: SHA-1 367
No Integrity Provided by Pure Hashing 368
Hash-Based Message Authentication Code, or Keyed Hash 369
Digital Signatures 370
Public Key Infrastructure 372
Symmetric Key Distribution Protected by Asymmetric Encryption 372
Public Key Distribution in Asymmetric Cryptography 373
PKI as a Trusted Third-Party Protocol 374
PKI: Generating Key Pairs 374
PKI: Distributing the Public Key of the Trusted Introducer 374
PKI: Requesting Signed Certificates 376
PKI: Signing Certificates 376
PKI: Providing Entities with Their Certificates 377
PKI: Exchanging Public Keys Between Entities Using Their
Signed Certificates 378
PKI Entities 379
X.509v3 Certificates 380
PKI Example: SSL on the Internet 381
Internet Web Browser: Embedded Internet-CA Certificates 382
Obtaining the Authentic Public Key of the Web Server 383
Web Server Authentication 384
Exchanging Symmetric Session Keys 385
Session Encryption 386
Summary 387
References 387
Review Questions 387
Chapter 15 Understanding Native CUCM Security Features and CUCM PKI 391
Chapter Objectives 391
CUCM Security Features Overview 391
CUCM Security Feature Support 393
Cisco Unified Communications Security Considerations 394
CUCM IPsec Support 395
IPsec Scenarios in Cisco Unified Communications 395
IPsec on Network Infrastructure Devices 397
Signed Phone Loads 397
SIP Digest Authentication 398
SIP Digest Authentication Configuration Procedure 399
SIP Digest Authentication Configuration Example 399
SIP Trunk Encryption 400
SIP Trunk Encryption Configuration Procedure 401
SIP Trunk Encryption Configuration 401
CUCM PKI 402
Self-Signed Certificates 402
Manufacturing Installed Certificates 403
Locally Significant Certificates 403
Multiple PKI Roots in CUCM Deployments 404
Cisco Certificate Trust List 405
Cisco CTL Client Function 406
Initial CTL Download 408
IP Phone Verification of a New Cisco CTL 409
IP Phone Usage of the CTL 410
PKI Topology with Secure SRST 410
Trust Requirements with Secure SRST 412
Secure SRST: Certificate Import: CUCM 412
Secure SRST: Certificate Import: Secure SRST Gateway 413
Certificate Usage in Secure SRST 414
Summary 415
References 416
Review Questions 416
Chapter 16 Implementing Security in CUCM 419
Chapter Objectives 419
Enabling PKI-Based Security Features in CUCM 420
Configuration Procedure for PKI-Based CUCM Security Features 421
Enabling Services Required for Security 422
Installing the Cisco CTL Client 422
Cisco CTL Client Usage 423
Setting the Cluster Security Mode 424
Updating the CTL 425
CAPF Configuration and LSC Enrollment 425
CAPF Service Configuration Parameter 426
CAPF Phone Configuration Options 426
First-Time Installation of a Certificate with a Manually Entered Authentication
String 428
Certificate Upgrade Using an Existing MIC 429
Generating a CAPF Report to Verify LSC Enrollment 430
Finding Phones by Their LSC Status 431
Signed and Encrypted Configuration Files 431
Encrypted Configuration Files 432
Obtaining Phone Encrypted Configuration Files 433
Configuring Encrypted Configuration Files 434
Phone Security Profiles 434
Default SCCP Phone Security Profiles 435
Configuring TFTP Encrypted Configuration Files 436
Secure Signaling 436
Certificate Exchange in TLS 438
Server-to-Phone Authentication 438
Phone-to-Server Authentication 439
TLS Session Key Exchange 440
Secure Signaling Using TLS 441
Secure Media Transmission Between Cisco IP Phones 441
SRTP Protection 442
SRTP Packet Format 443
SRTP Encryption 443
SRTP Authentication 444
Secure Call Flow Summary 445
Configuring IP Phones to Use Secure Signaling and Media Exchange 446
The Actual Security Mode Depends on the Configuration of Both Phones 447
Secure Media Transmission to H.323 and MGCP Gateways 447
H.323 SRTP CUCM 448
SRTP to MGCP Gateways 450
Secure Conferencing 450
Secure Conferencing Considerations 451
Secure Conferencing Configuration Procedure 452
Summary 458
References 459
Review Questions 459
Appendix A Answers to Chapter Review Questions 465
Index 472
