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Cisco IP Telephony
Network Design Guide
Cisco CallManager Release 3.0(5)
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Text Part Number: 78-11103-03

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xiv
Conventions
xv
Additional Information
xvii
Obtaining Documentation
xviii
World Wide Web
xviii
Documentation CD-ROM
xviii
Ordering Documentation
xviii
Documentation Feedback
xix
Obtaining Technical Assistance
xix
Cisco.com
xix
Technical Assistance Center
xx
Contacting TAC by Using the Cisco TAC Website
xx
Contacting TAC by Telephone
xxi
CHAPTER

1
Introduction
1-1

Power to IP Phones
2-10
Inline Power
2-10
Establishing Power to the IP Phone
2-12
Inline Power Configuration
2-13
Other Inline Power Considerations
2-15
External Patch Panel Power
2-17
Wall Power
2-20
Summary of Recommendations
2-20
IP Addressing and Management
2-21
CDP Enhancements
2-22
VVID Field
2-22
Trigger Field
2-22
Power Requirement Field
2-23
Auxiliary VLANs and Data VLANs
2-23
Voice VLAN Configuration
2-24

Device Weights
3-3
Intracluster Communication
3-5
Cisco CallManager Redundancy
3-6
Redundancy Group Configurations
3-6
Device Pool Configuration
3-9
Campus Clustering Guidelines
3-12
Intercluster Communication
3-14
Cluster Provisioning for the Campus
3-14
Clusters for Multisite WAN with Distributed Call Processing
3-15
Clusters for Multisite WAN with Centralized Call Processing
3-18
Intracluster and Intercluster Feature Transparency
3-21

Contents
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CHAPTER

4

CHAPTER

5
Dial Plan Architecture and Configuration
5-1
Cisco CallManager Dial Plan Architecture
5-1
Route Pattern
5-6
Route List
5-7
Route Group
5-7
Devices
5-8
Digit Translation Tables
5-9
Special Dial String Considerations
5-10
On-Net Route Pattern
5-11
Outbound Calls Through the PSTN
5-12

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Contents
Configuring Dial Plan Groups and Calling Restrictions
5-14

6-15
Dial Plan Considerations
6-15
Using Cisco CallManager to Route Calls
6-17
Using the Gatekeeper to Route Calls
6-19
Cisco CallManager Configuration
6-22
Gatekeeper Configuration
6-27
Gatekeeper Selection and Redundancy
6-28
Configuring Dialing Restrictions
6-28
Bandwidth Consumption of Dialed Numbers
6-28
Cisco CallManager Cluster Considerations
6-30
DSP Resource Provisioning for Transcoding and Conferencing
6-30
Voice Messaging Considerations
6-32

Contents
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CHAPTER


Campus QoS Model
8-1
Traffic Classification
8-2
Interface Queuing
8-2
WAN QoS Model
8-4
WAN Provisioning
8-4
WAN QoS Tools
8-5
Traffic Prioritization
8-5
Link Efficiency Techniques
8-7
Traffic Shaping
8-9
Best Practices
8-10
Call Admission Control
8-11

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Contents
CHAPTER

9

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
10-6
Detailed Discussion of Model A
10-7
Detailed Discussion of Model B
10-12
Detailed Discussion of Model C
10-15
Detailed Discussion of Model D
10-18
Cisco Digital PBX Adapter (DPA)
10-20
Understanding How the DPA 7630 Works
10-21
Why is the DPA 7630 Needed?
10-21

Contents
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Can I Just Use SMDI?
10-21

11-12
Trace Path Analysis
11-13
Resource Manager Essentials
11-15
Inventory Control and Reporting
11-15
System Logging Management
11-16
Syslog Message Filtering
11-18
Alarms
11-19
GLOSSARY
INDEX

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Preface
This preface describes the purpose, intended audience, organization, and conventions
for the Cisco IP Telephony Network Design Guide.
Purpose
This document serves as an implementation guide for Cisco AVVID (Architecture
for Voice, Video and Integrated Data) networks based on Cisco CallManager
Release 3.0(5). With such a high level of industry interest regarding IP telephony,
customers are aggressively pursuing Cisco solutions for both large and small
networks. Solutions based on Cisco CallManager Release 3.0(5) allow Cisco to
deliver large-scale IP telephony systems with many capabilities.
However, it is important to ensure that these systems fit successfully within a set

Discusses issues to consider when preparing a LAN
infrastructure for a Cisco AVVID solution.
Chapter 3 Cisco CallManager Clusters Discusses the concept, provisioning, and
configuration of Cisco CallManager clusters.
Chapter 4 Gateway Selection Discusses issues concerning the selection of gateways
for connecting an IP telephony network to the PSTN
or to legacy PBX and key systems.
Chapter 5 Dial Plan Architecture and
Configuration
Discusses the architecture and operation of the
Cisco CallManager dial plan and provides design
recommendations for campus environments.
Chapter 6 Multisite WAN with Distributed
Call Processing
Provides design guidelines for multi-site WAN
systems using Cisco CallManager Release 3.0(5) for
distributed call processing.

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Preface
Organization
Chapter 7 Multisite WAN with Centralized
Call Processing
Provides design guidelines for multi-site WAN
systems using Cisco CallManager Release 3.0(5) for
centralized call processing.
Chapter 8 Quality of Service Addresses the QoS requirements for Cisco AVVID
implementations over the enterprise WAN.

Revised document for Cisco CallManager Release 3.0(5).
•
Updated details of campus infrastructure design in
Chapter 2.
•
Revised bandwidth requirements for inter-cluster calls in
Chapter 3.
•
Updated gateway information in Chapter 4.
•
Added gatekeeper information to Chapter 5.
•
Updated details of call admission control and gatekeepers
in Chapter 6.
•
Revised major portions of the Quality of Service (QoS)
information in Chapter 8.
•
Updated details of Catalyst DSP provisioning in
Chapter 9.
•
Removed the chapter on Cisco uOne from this book. This
information will be covered in a separate document.
•
Updated migration information in Chapter 10.
06/30/00
•
Reformatted document to allow for online display.
•
Updated details of cluster provisioning in Chapter 3.

Information you must enter is in
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brackets.

Preface
Conventions
xvi
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Notes use the following conventions:
Note
Means reader take note. Notes contain helpful suggestions or
references to material not covered in the publication.
Timesavers use the following conventions:
Timesaver
Means the described action saves time. You can save time by
performing the action described in the paragraph.
Tips use the following conventions:
Tips
Means

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Internet Message Access Protocol (IMAP):
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http://www.imap.org/whatisIMAP.html
•
Lightweight Directory Access Protocol Version 3 (LDAPv3):
–
http://www.critical-angle.com/ldapworld/ldapv3.html
•
Glossary of terms and acronyms:
–
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ita/index.htm
–
http://www.cisco.com/univercd/cc/td/doc/product/voice/index.htm

Preface
Obtaining Documentation
xviii
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Obtaining Documentation
The following sections provide sources for obtaining documentation from Cisco
Systems.

xix
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Preface
Obtaining Technical Assistance
Documentation Feedback
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Preface
Obtaining Technical Assistance
If you cannot resolve your technical issue by using the TAC online resources,
Cisco.com registered users can open a case online by using the TAC Case Open
tool at the following website:
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design models discussed in this guide. This scenario represents what is possible
with Cisco CallManager Release 3.0(5).

Chapter 1 Introduction
General Design Models
1-2
Cisco IP Telephony Network Design Guide
78-11103-03
Figure 1-1 Composite Model
Large campus
(Up to 10,000 users)
Telecommuter
(Without local call processing)
Branch office
(With local call processing)
Branch office
(Without local call processing)
V
V
V
IP WAN
Rest of
world
Cisco IOS
gatekeeper
PSTN
IP
IP
IP
V

•
Multisite IP WAN with Distributed Call Processing, page 1-7
•
Multisite IP WAN with Centralized Call Processing, page 1-10
The following sections summarize the design goals and implementation
guidelines for each of these models.
Single-Site Model
Figure 1-2 illustrates the model for an IP telephony network within a single
campus or site.