Cisco IP Telephony Solution Reference Network Design Guide

Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA http://www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 Cisco IP Telephony Solution Reference Network Design Guide Cisco CallManager Release 3.1 and 3.2 July 2003 Customer Order Number: 956378 Text Part Number: EDCS-197018 THE SPECIFICATIONS AND INFORMATION REGARDING THE PRODUCTS IN THIS MANUAL ARE SUBJECT TO CHANGE WITHOUT NOTICE. ALL STATEMENTS, INFORMATION, AND RECOMMENDATIONS IN THIS MANUAL ARE BELIEVED TO BE ACCURATE BUT ARE PRESENTED WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. USERS MUST TAKE FULL RESPONSIBILITY FOR THEIR APPLICATION OF ANY PRODUCTS. THE SOFTWARE LICENSE AND LIMITED WARRANTY FOR THE ACCOMPANYING PRODUCT ARE SET FORTH IN THE INFORMATION PACKET THAT SHIPPED WITH THE PRODUCT AND ARE INCORPORATED HEREIN BY THIS REFERENCE. IF YOU ARE UNABLE TO LOCATE THE SOFTWARE LICENSE OR LIMITED WARRANTY, CONTACT YOUR CISCO REPRESENTATIVE FOR A COPY. 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(0304R) iii Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 CONTENTS Preface xiii Purpose xiii Scope xiii Audience xiii Organization xiii Obtaining Documentation xv World Wide Web xv Documentation CD-ROM xv Ordering Documentation xv Documentation Feedback xv Obtaining Technical Assistance xvi Cisco.com xvi Technical Assistance Center xvi Cisco TAC Web Site xvii Cisco TAC Escalation Center xvii CHAPTER 1 Overview of Cisco AVVID IP Telephony Solutions 1-1 Why IP Telephony? 1-1 Architecture Overview 1-3 Security 1-4 Quality of Service 1-4 Network Management 1-4 Cisco CallManager Deployment Models 1-5 Single-Site Call Processing Model 1-5 Multi-Site WAN Model with Centralized Call Processing 1-5 Multi-Site WAN Model with Distributed Call Processing 1-6 Clustering Over the IP WAN 1-6 Applications 1-7 Cisco IP SoftPhone 1-7 Extension Mobility 1-7 Multi-Party Voice Conferencing 1-8 Unified Messaging 1-8 Web Services for IP Phones 1-8 Cisco Personal Assistant 1-9 Contents iv Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 Cisco Customer Response Solutions Platform 1-10 Cisco IP Integrated Contact Distribution (IP ICD) 1-10 Cisco IP Interactive Voice Response (IP IVR) 1-11 Components That Apply to All Deployment Models 1-11 Voice, Fax, and Modem Gateways 1-11 Station Devices 1-12 Emergency Services (911 and E911) 1-12 CHAPTER 2 IP Telephony Deployment Models 2-1 Single Site 2-2 Solution Benefits 2-3 Best Practices 2-4 Dial Plan 2-4 Multi-Site WAN with Centralized Call Processing 2-4 Solution Benefits 2-6 Best Practices 2-6 Remote Site Survivability 2-7 Call Admission Control 2-9 Recommendations for Locations and Call Admission Control 2-11 Gateways 2-11 Dial Plan 2-11 Multi-Site WAN with Distributed Call Processing 2-13 Solution Benefits 2-15 Best Practices 2-15 Call Processing Agents 2-15 Call Admission Control 2-16 Dial Plan 2-17 Site Dial Plan 2-18 Gatekeeper Dial Plan 2-20 Hybrid Dial Plan 2-20 Clustering Over the IP WAN 2-21 Local Failover Deployment Model 2-22 Cisco CallManager Provisioning 2-23 Gateways 2-24 Voice Mail 2-24 Music on Hold 2-24 Remote Failover Deployment Model 2-25 Cisco CallManager Provisioning 2-26 Gateways 2-26 Contents v Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 Voice Mail 2-27 Music on Hold 2-27 CHAPTER 3 Network Infrastructure Requirements for IP Telephony 3-1 LAN Infrastructure 3-3 Traffic Classification 3-4 Interface Queuing 3-4 Bandwidth Provisioning 3-4 WAN Infrastructure 3-5 Bandwidth Provisioning 3-6 Provisioning for Voice Bearer Traffic 3-7 Provisioning for Call Control Traffic with Centralized Call Processing 3-8 Provisioning for Call Control Traffic with Distributed Call Processing 3-10 Traffic Prioritization 3-12 Link Efficiency Techniques 3-13 Traffic Shaping 3-15 CHAPTER 4 Choosing a Cisco IP Telephony Gateway 4-1 Understanding Cisco Gateways 4-1 Cisco Access Analog Gateways 4-1 Cisco Access Digital Trunk Gateways 4-2 Gateway Requirements 4-2 Gateway Protocols 4-2 Selecting the Gateway Protocol 4-3 Gateway Protocol and Core Feature Requirements 4-4 DTMF Relay 4-5 SCCP Gateways 4-5 H.323 Gateways 4-5 MGCP Gateway 4-5 Supplementary Services 4-5 SCCP Gateways 4-6 H.323 Gateways 4-6 MGCP Gateway 4-7 Cisco CallManager Redundancy 4-8 SCCP Gateways 4-8 H.323 Gateways 4-9 MGCP Gateway 4-9 Call Survivability in Cisco CallManager 4-10 Endpoint Rules for Gateway Call Survivability 4-10 Contents vi Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 Site-Specific Gateway Requirements 4-11 Q.SIG Support 4-12 Site Specific Gateway Features Summary 4-13 Summary 4-16 CHAPTER 5 Transcoding, Conferencing, and MTP Resources 5-1 Media Resource Types 5-1 Media Termination Point (MTP) 5-1 Transcoder 5-2 Unicast Conference Bridge 5-2 MTP and Transcoding Resources 5-3 Software MTP Resources 5-4 Hardware MTP and Transcoding Resources 5-4 Catalyst 4000 MTP and Transcoding Services 5-5 Catalyst 6000 MTP and Transcoding Services 5-5 Cisco Catalyst MTP Constraints 5-6 Cisco VG200 MTP and Transcoding Services 5-7 Cisco ICS 7750 MTP and Transcoding Services 5-7 Provisioning MTP and Transcoding Resources 5-8 Application Scenarios 5-9 Single-Site Deployments 5-10 Multi-Site WAN Deployments with Centralized Call Processing 5-10 Multi-Site WAN Deployments with Distributed Call Processing 5-11 IP PSTN Access 5-12 Conferencing Resources 5-13 Software Conferencing Resources 5-15 Hardware Conferencing Resources 5-16 Catalyst 4000 Conferencing Services 5-16 Catalyst 6000 Conferencing Services 5-17 Cisco VG200 Conferencing Services 5-18 Provisioning Conference Resources 5-19 Application Scenarios 5-19 Single-Site Deployments 5-19 Multi-Site WAN Deployments with Centralized Call Processing 5-19 Multi-Site WAN Deployments with Distributed Call Processing 5-22 CHAPTER 6 Call Processing with Cisco CallManager 6-1 Cluster Operation and Scalability Guidelines 6-1 Device Weights 6-3 Contents vii Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 Server Memory Requirements 6-7 Intracluster Communication 6-7 Cisco CallManager Redundancy 6-8 Redundancy Group Configuration 6-9 Device Pool Configuration 6-10 Clustering Guidelines 6-12 Intercluster Communication 6-13 Cluster Provisioning for the Campus 6-14 Clusters for Multi-site WAN with Distributed Call Processing 6-16 Clusters for Multi-site WAN with Centralized Call Processing 6-18 The Effects of Network Delay on Call Processing 6-18 Clustering Over the WAN 6-19 WAN Considerations 6-19 Intra-Cluster Communications 6-20 Local Failover Deployment Model 6-21 Remote Failover Deployment Model 6-24 Common Design Guidelines for Clustering over the WAN 6-26 Media Resources 6-33 Survivable Remote Site Telephony (SRST) 6-35 SRST Features and Requirements 6-37 SRST Design Considerations 6-38 SRST with Automated Attendant 6-40 CHAPTER 7 Call Admission Control 7-1 Bandwidth Calculations 7-2 Call Admission Control with Cisco CallManager Locations 7-2 Call Admission Control with a Gatekeeper 7-4 Gatekeeper Operations 7-5 Gatekeeper Discovery 7-5 Registration Process 7-6 Admission Requests 7-7 Disengage Request 7-8 Bandwidth Requests 7-8 Technology Prefix 7-9 E.164 Address Resolution 7-9 ARQ Parsing Order 7-10 Cisco IOS Gatekeeper Commands 7-10 Debug Commands 7-11 Cisco CallManager Configuration 7-11 Contents viii Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 Gatekeeper Used for Call Admission Control 7-12 Gateway Configuration 7-13 Intercluster Trunk Gateways 7-16 Summary of Call Admission Control 7-18 CHAPTER 8 Dial Plan 8-1 Overview of IP Telephony Dial Plans 8-2 Dial Plan Components and Operation 8-4 External Route Pattern Architecture 8-5 Route Patterns 8-7 Route Lists 8-11 Route Groups 8-14 Devices 8-15 Calling Restrictions 8-16 Partitions 8-16 Calling Search Spaces 8-16 Translation Patterns 8-19 Voice Mail Integration and Cisco CallManager Dial Plans 8-21 Voice Mail Integration via SCCP 8-23 Voice Mail Integration via SMDI 8-23 Dial Plan Guidelines for IP Telephony Deployment Models 8-25 Single-Site Deployment 8-26 Multi-Site IP WAN with Distributed Call Processing 8-28 Route Pattern Structure 8-29 Partitions and Calling Search Spaces 8-30 Multi-Site IP WAN with Centralized Call Processing 8-30 Route Pattern Structure 8-31 Partitions and Calling Search Spaces 8-32 Multi-Site IP WAN with Overlapping Extensions 8-33 Partitions and Calling Search Spaces 8-34 Outbound Calls 8-35 Inter-Site Calls 8-35 Incoming Calls 8-36 Voice Mail Considerations 8-36 CHAPTER 9 Voice Mail Integration with Cisco CallManager 9-1 Cisco CallManager and Voice Mail 9-1 Existing Versus New Voice Mail Systems 9-4 Voice Mail and Cisco CallManager Release 3.2 9-6 Contents ix Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 Cisco Unity 9-7 Cisco Digital PBX Adapter (DPA) 9-9 Understanding How the DPA Works 9-10 Why is the DPA Needed? 9-10 Can I Just Use SMDI? 9-10 What If I Cannot Use SMDI? 9-10 Choosing an Integration Mode 9-11 Using the Simple Integration Mode 9-11 Using the Hybrid Integration Mode 9-12 Using the Multiple Integration Mode 9-13 CHAPTER 10 Migration to an IP Telephony Network 10-1 Network Models 10-1 PBX and Voice Messaging Interfaces and Protocols 10-2 Simple IP Network Migration Sequence 10-3 Reference Models for Migration Configurations 10-5 Detailed Discussion of Model A 10-6 Detailed Discussion of Model B 10-9 Detailed Discussion of Model C 10-11 Detailed Discussion of Model D 10-13 Cisco Digital PBX Adapter (DPA) 10-14 Understanding How the DPA 7630 Works 10-15 Why is the DPA 7630 Needed? 10-15 Can I Just Use SMDI? 10-15 What If I Cannot Use SMDI? 10-15 Choosing an Integration Mode 10-16 Using the Simple Integration Mode 10-16 Using the Hybrid Integration Mode 10-17 Using the Multiple Integration Mode 10-18 CHAPTER 11 CTI Applications Architecture and Design 11-1 Cisco CallManager Application Interfaces 11-1 CTI Architecture 11-3 Cisco CallManager Server 11-3 CTI Application Platform 11-4 CTI Devices 11-4 CTI Manager 11-5 CTI Manager Configuration 11-7 CTI Manager Provisioning 11-8 Contents x Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 Ensuring Normal Operations 11-12 CTI Redundancy 11-12 CTI Fail-Back 11-14 CTI Design Consideration 11-14 Scalability 11-14 Application Scalability 11-15 Cisco CallManager Scalability 11-15 Grouping CTI devices 11-21 Redundancy 11-22 General Redundancy Considerations 11-22 Redundancy Considerations for Single-Site Call Processing Deployments 11-23 Redundancy Considerations for a Multi-Site WAN with Centralized Call Processing 11-23 Redundancy Considerations for a Multi-Site WAN with Distributed Call Processing 11-25 Quality of Service 11-26 Example of CTI Provisioning for Scalability and Redundancy 11-27 System Profile 11-28 Design Assumptions 11-28 Design Approach 11-29 Identify CTI Resources 11-29 Calculate Package Weights for Each Application 11-29 Group the CTI Devices into Device Pools 11-31 Provision the CTI Resources on the Cisco CallManager and CTI Manager Servers 11-31 Provision Backup Servers for Failover Conditions 11-33 Summary 11-35 CHAPTER 12 Cisco IP IVR System Design Considerations 12-1 IP IVR Architecture 12-1 Cisco CallManager Device Weight Provisioning for IP IVR 12-2 Additional IP-IVR Scalability Considerations 12-3 IP IVR Co-Resident with Cisco CallManager 12-3 Standalone IP IVR Configuration 12-3 Redundancy Considerations 12-4 CTI Manager Fails 12-4 Cisco CallManager Server Fails 12-6 IVR Application Fails 12-6 Summary 12-8 [...]... http://www .cisco. com/univercd/cc/td/doc/product/voice/assist/index.htm Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 1-9 Chapter 1 Overview of Cisco AVVID IP Telephony Solutions Applications Cisco Customer Response Solutions Platform Cisco IP Telephony Solutions for the Enterprise provides all of the components you need to design and deploy a complete IP telephony solution The Cisco Customer Response Solutions (CRS) platform... – Cisco IP SoftPhone – Extension mobility – Multi-party voice conferencing – Unified messaging – Web services for IP phones – Cisco Personal Assistant – Cisco Customer Response Solutions (CRS) platform – Cisco IP Integrated Contact Distribution (IP ICD) – Cisco IP Interactive Voice Response (IP IVR) Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 1-3 Chapter 1 Overview of Cisco. .. Cisco IP IVR System Design Considerations Describes the IP IVR architecture and how it affects call processing with Cisco CallManager 13 Cisco IP SoftPhone Design Considerations Lists a few key design considerations for deploying Cisco IP SoftPhones in your IP telephony system 14 Directory Access for Cisco IP Telephony Endpoints Describes how to provide Cisco IP Telephony endpoints, such as Cisco IP. .. illustrates the model for an IP telephony network within a single campus or site Cisco IP Telephony Solution Reference Network Design Guide 2-2 EDCS-197018 Chapter 2 IP Telephony Deployment Models Single Site Figure 2-1 Single-Site Model Msg store Msg store LDAP directory Cisco Unity M Cisco CallManager cluster M M M M IP IP IP WAN IP IP PSTN Catalyst wiring closet 74351 Catalyst backbone Solution Benefits A... IP Phones and Cisco IP SoftPhone, with access to a corporate LDAP directory 15 Security Recommendations for IP Telephony Presents various considerations and options for securing your IP telephony system 16 Network Management Recommendations for IP Telephony Describes some of the tools available for managing your IP telephony network Cisco IP Telephony Solution Reference Network Design Guide xiv EDCS-197018... Using CiscoWorks Internetwork Performance Monitor (IPM) Additional References 16-8 16-9 Cisco IP Telephony Solution Reference Network Design Guide xii EDCS-197018 Preface This preface describes the purpose, scope, intended audience, and general organization of this Cisco IP Telephony Solution Reference Network Design Guide It also provides information on how to order documentation from Cisco Systems Purpose... flexibility of IP networks The Cisco CallManager user interface simplifies the most common subscriber and telephony configuration tasks by building upon legacy telephony administration systems and adding software and web-based applications Cisco IP Telephony Solution Reference Network Design Guide 1-4 EDCS-197018 Chapter 1 Overview of Cisco AVVID IP Telephony Solutions Cisco CallManager Deployment Models Cisco. .. typical IP telephony solution employing the Cisco AVVID network infrastructure, with Cisco CallManager as the call processing agent Figure 1-1 Typical IP Telephony Solution Headquarters Branch (with Call Processing and Applications) Applications (Voice mail, IVR, ICD, ) M M M M M M Cisco CallManager cluster M M V IP GK IP PSTN Branch (with SRST and Applications) V IP IP IP WAN IP IP 74350 Rest of world Cisco. .. single solution for small or medium sites For further information on clustering over the WAN, refer to the chapter on Call Processing with Cisco CallManager Cisco IP Telephony Solution Reference Network Design Guide 1-6 EDCS-197018 Chapter 1 Overview of Cisco AVVID IP Telephony Solutions Applications Applications The following applications enhance the capabilities of the Cisco AVVID IP Telephony solution: ... world Cisco IP Telephony Solution Reference Network Design Guide 1-2 EDCS-197018 Chapter 1 Overview of Cisco AVVID IP Telephony Solutions Architecture Overview Architecture Overview The foundation architecture of the Cisco AVVID IP Telephony solution consists of four primary components (see Figure 1-1): • Cisco AVVID Network Infrastructure The infrastructure includes public switched telephone network (PSTN) . toward IP is happening now. 1-2 Cisco IP Telephony Solution Reference Network Design Guide EDCS-197018 Chapter 1 Overview of Cisco AVVID IP Telephony Solutions. Solution Reference Network Design Guide EDCS-197018 Preface Obtaining Technical Assistance CHAPTER 1-1 Cisco IP Telephony Solution Reference Network Design