Implementing Cisco Unified Communications Manager

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