Nortel VoIP Gateway Configuration Manual

Norstar VoIP Gateway Configuration Guide

Part No. P0606298 02 August 11, 2003

recommendations in this document are believed to be accurate and reliable, but are presented without express or implied warranty. Users must take full responsibility for their applications of any products specified in this document. The information in this document is proprietary to Nortel Networks NA Inc.

Trademarks

NORTEL NETWORKS, Norstar and Meridian are trademarks of Nortel Networks. Microsoft, MS, MS-DOS, Windows, and Windows NT are registered trademarks of Microsoft Corporation. All other trademarks and registered trademarks are the property of their respective owners.

P0606298 02

Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Before you begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Symbols used in this guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Text conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Related publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

How to get help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Chapter 1

About Norstar VoIP Gateway. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

VoIP Gateway key features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Chapter 2

IP Telephony overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Presales Support (CSAN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Supported H.323 features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Key IP telephony concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

VoIP trunks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

VoIP trunks and analog/digital telephones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Gatekeepers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Codecs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Jitter Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

QoS routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Prerequisites checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Network diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Network devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Network assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Chapter 3

Configuring the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Computer requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Accessing the web interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Configuring the Protocol Definition parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Configuring the Registration Prefixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Configuring the Number Manipulation tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Number Manipulation overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Basic Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Configuring number manipulation for Destination Phone Numbers for Norstar to IP calls 46

Configuring number manipulation for Digit Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Configuring number manipulation for Source Phone Numbers for IP to Norstar calls . . 52 Configuring number manipulation for Source Phone Numbers for Norstar to IP calls . . 55

Norstar VoIP Gateway Configuration Guide

4 Contents

Configuring the Channels to Hunt Group parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Configuring the Automatic Dialing phone numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Configuring the Caller ID Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Configuring the Telephone to IP Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Configuring the IP to Hunt Group Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Configuring Call Forwarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Configuring the Network Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

Configuring the Channel Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Configuring the VoIP Gateway time and date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Chapter 4

Configuring the VoIP Gateway using the INI file . . . . . . . . . . . . . . . . . . . . . . . . . 85

Retrieving the INI file from the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Loading the INI file on the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

Contents of the INI file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Using VoIP Gateway features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Basic, Logging and Web parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Channel parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

H.323 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

The INI file structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

The INI file structure rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

The INI file example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Chapter 5

Configuring the Norstar system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Configuring your Norstar KSU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Required Norstar hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Configuring the trunks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Configuration tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Configuring the Norstar system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Shared line settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Dedicated lines settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Example configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Configuring a simple Norstar network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Setting up the dialing plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Setting up the Norstar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Setting up the VoIP Gateway dialing plan – Hunt Groups . . . . . . . . . . . . . . . . . . . 120

Setting up the VoIP Gateway dialing plan – IP Routing Table . . . . . . . . . . . . . . . . . 120

Setting up the VoIP Gateway dialing plan – Caller ID table . . . . . . . . . . . . . . . . . . 121

Setting up the VoIP Gateway dialing plan – Number Type . . . . . . . . . . . . . . . . . . . 122

Setting up the VoIP Gateway dialing plan – Digit Delivery . . . . . . . . . . . . . . . . . . . 122

Setting up the VoIP Gateway dialing plan – destination Hunt Group assignment . 123

Setting up the VoIP Gateway – Fast Start parameters . . . . . . . . . . . . . . . . . . . . . . 124

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Contents 5

Setting up the VoIP Gateway – H.323 parameters . . . . . . . . . . . . . . . . . . . . . . . . . 124

Setting up the VoIP Gateway to control the Call Progress Tone . . . . . . . . . . . . . . . 125

Setting up the VoIP Gateway to enable end to end DTMF tones . . . . . . . . . . . . . . . . . 125

Setting up the VoIP Gateway to use a RAD over VoIP trunks . . . . . . . . . . . . . . . . . . . . 126

Connections required for the RAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Configuring the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Setting up the VoIP Gateway for T.38 Fax Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Enabling Fax support on the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Setting up the dialing plan on the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . 128

Setting up the VoIP Gateway to use a Radvision Gatekeeper . . . . . . . . . . . . . . . . . . . 129

Configuring the H.323 Protocol Definition settings . . . . . . . . . . . . . . . . . . . . . . . . . 129

Configuring the Gatekeeper Registration of the dialing plan . . . . . . . . . . . . . . . . . 130

Configuring the Business Communications Manager as an endpoint . . . . . . . . . . . . . . 130

Considerations with Business Communications Manager . . . . . . . . . . . . . . . . . . . 130

Considerations when using a Meridian 1 IPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Considerations when using a CSE1K Gatekeeper . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Chapter 6

Changing the VoIP Gateway password . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Chapter 7

Upgrading the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Upgrading the software on the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Loading the software file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Loading a configuration file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Backing up the VoIP Gateway configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Restoring the VoIP Gateway configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Chapter 8

Diagnostics and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

VoIP Gateway LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

VoIP Gateway Self-Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

Rapid self-test mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

Detailed self-test mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

RS-232 terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Connecting a terminal to the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Configuring a terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Viewing the terminal information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

SysLog Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Sending the SysLog Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Setting the SysLog Server IP Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Activating the SysLog Client . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

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6 Contents

Appendix A

Numbering and Dial Plans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

Public and Private Numbering Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

Dialing Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

Numbering Plans in H.323 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

Planning Your Numbering Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

Configuring Numbering Plans in the Norstar VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . 150

Appendix B

Efficient Networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Determining the bandwidth requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Network engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154

Additional feature configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160

Further network analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

Post-installation network measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144

Possible common problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Possible H.323 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Determining WAN link resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Link utilization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

Bandwidth requirements on half duplex links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

Bandwidth requirements on full duplex links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

LAN engineering examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

WAN engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

Determining network loading caused by IP telephony traffic . . . . . . . . . . . . . . . . . . . . 160

Enough link capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

Not enough link capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

Other intranet resource considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

Implementing the network, LAN engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

Components of delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

Reducing link delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

Reducing hop count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

Adjust the jitter buffer size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164

Reduce packet errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

Routing issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

Appendix C

Silence compression. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

Silence Compression on Half Duplex Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168

Silence compression on Full Duplex Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

Comfort noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

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Appendix D

Network performance utilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

Ping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

Traceroute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173

Sniffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

Appendix E

Interoperability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Business Communications Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Local Gateway IP Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175

Media Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176

Remote Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Meridian 1 ITG / IPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .178

CSE 1000 Gatekeeper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Adding an H.323 Endpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

Setting H.323 Endpoint Dialing Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Committing Gatekeeper Configuration Changes . . . . . . . . . . . . . . . . . . . . . . . . . . 180

Programming the VoIP Gateway to work with a CSE 1000 Gatekeeper . . . . . . . . . . . . 180

Radvision Gatekeeper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

General Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181

General Gateway Setup for Radvision ECS Gatekeeper Interoperability . . . . . . . . . . . 182

Setting up the Numbering Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

Setting up Remote Routers for IP Telephony Prioritization . . . . . . . . . . . . . . . . . . . . . . . . . 184

Creating an outbound traffic filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184

Sample criteria, ranges, and actions for UDP filtering . . . . . . . . . . . . . . . . . . . . . . 185

Appendix F

Quality of Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Measuring Intranet QoS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Measuring end-to-end network delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187

Measuring end-to-end packet loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

Recording routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

Adjusting Ping measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Adjustment for processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Late packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

Measurement procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

Other measurement considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

Decision: does the intranet meet IP telephony QoS needs? . . . . . . . . . . . . . . . . . 191

Implementing QoS in IP networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

Traffic mix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

TCP traffic behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192

Norstar VoIP Gateway Configuration Guide

8 Contents

Appendix G

SNMP Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

SNMP Message Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

SNMP MIB Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

SNMP Extensibility feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195

VoIP Gateway supported MIBs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195

Appendix H

Working with H.450 supplementary services . . . . . . . . . . . . . . . . . . . . . . . . . . 197

Call Hold and Retrieve features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

Appendix I

Alternate (Redundant) Gatekeeper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

Appendix J

DTMF, Fax and Modem transport modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

Consultation\Alternate feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

Call Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198

Call Forward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198

DTMF/MF Relay Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

Fax/Modem Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

Configuring Fax Relay Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204

Configuring Fax/Modem ByPass Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

Supporting V.34 Faxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

Appendix K

Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

VoIP Gateway specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

Default RTP/RTCP/T.38 Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

Industry standard packet types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

VoIP Gateway specific payload types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215

P0606298 02

Figures

Figure 1 Norstar VoIP Gateway front panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 2 Typical VoIP Gateway application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 3 Web browser login screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 4 Protocol Definition screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 5 Registration Prefixes Table screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Figure 6 Destination Phone Number Manipulation Table for TEL->IP calls screen . . . . . 47

Figure 7 Digit Delivery Table screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Figure 8 Source Phone Number Manipulation Table for IP->TEL calls screen . . . . . . . . 53

Figure 9 Source Phone Number Manipulation Table for TEL->IP calls screen . . . . . . . . 56

Figure 10 End Point’s Phone Number table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Figure 11 Automatic Dialing Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Figure 12 Caller Display Info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Figure 13 Phone to IP Routing Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Figure 14 IP to Hunt Group Routing Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Figure 15 Call Forward Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Figure 16 Network Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Figure 17 Channel Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Figure 18 Regional Settings screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Figure 19 Configuration File screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Figure 20 Configuration File screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

Figure 21 INI File Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Figure 22 VoIP Gateway INI file example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Figure 23 Example of IP to Hunt Group Routing settings for shared lines . . . . . . . . . . . . 113

Figure 24 Example of Digit Delivery Settings for shared lines . . . . . . . . . . . . . . . . . . . . . 114

Figure 25 Example of Channels - Hunt Group settings for dedicated lines . . . . . . . . . . . 115

Figure 26 Example of Caller Display Info settings for dedicated lines . . . . . . . . . . . . . . . 115

Figure 27 Example of IP to Hunt Group Routing Table settings for dedicated lines . . . . . 116

Figure 28 Simple Norstar and VoIP Gateway network . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Figure 29 Channels - Hunt Group screen for simple Norstar network . . . . . . . . . . . . . . . 120

Figure 30 Tel To IP Routing & IP Security screen for a simple Norstar network . . . . . . . . 121

Figure 31 Caller Display Info screen for a simple Norstar network . . . . . . . . . . . . . . . . . . 121

Figure 32 Destination Phone Number Manipulation Table for TEL->IP calls screen for

Figure 33 Digit Delivery Table screen for a simple Norstar network . . . . . . . . . . . . . . . . . 123

Figure 34 IP to Hunt Group Routing Table screen for a simple Norstar network . . . . . . . 124

Figure 35 Using a RAD over the VoIP Gateway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Figure 36 VoIP Gateway with T.38 Fax Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Figure 37 VoIP Gateway with a Gatekeeper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Figure 38 Change Password screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Figure 39 RS-232 cable wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

a simple Norstar network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Norstar VoIP Gateway Configuration Guide

10 Figures

Figure 40 Status and Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Figure 41 E.164 Numbering Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

Figure 42 Example of the Registration Prefixes Table . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

Figure 43 Example Destination Phone Number Manipulation Table . . . . . . . . . . . . . . . . 151

Figure 44 LAN engineering peak transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

Figure 45 Peak traffic, WAN link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

Figure 46 Calculating network load with IP telephony traffic . . . . . . . . . . . . . . . . . . . . . . 160

Figure 47 Network loading bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

Figure 48 One call on a half duplex link without silence compression . . . . . . . . . . . . . . . 168

Figure 49 One call on a half duplex link with silence compression . . . . . . . . . . . . . . . . . 168

Figure 50 Two calls on a half duplex link with silence compression . . . . . . . . . . . . . . . . . 169

Figure 51 One call on a full duplex link without silence compression . . . . . . . . . . . . . . . . 170

Figure 52 One call on a full duplex link with silence compression . . . . . . . . . . . . . . . . . . 171

Figure 53 Two calls on a full duplex link with silence compression . . . . . . . . . . . . . . . . . 172

P0606298 02

Tables

Table 1 Network diagram prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Table 2 Network device checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 3 Network assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 4 Protocol Definition parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 5 Registration Prefixes Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Table 6 Destination Phone Number Manipulation Table for TEL->IP calls (Norstar to IP) 48

Table 7 Digit Delivery Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Table 8 Source Phone Number Manipulation Table for IP->TEL calls (IP to Norstar) . . . 54 Table 9 Source Phone Number Manipulation Table for TEL->IP calls (Norstar to IP) . . . 56

Table 10 End Point’s Phone Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Table 11 Call Forward parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Table 12 Network Settings Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Table 13 Channel Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Table 14 Basic and Logging parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Table 15 Channel parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

Table 16 H.323 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Table 17 Using the VoIP Gateway features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Table 18 Norstar trunk configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Table 19 Dialing plan for simple Norstar network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Table 20 Software file types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Table 21 Indicator LEDs on the VoIP Gateway front panel . . . . . . . . . . . . . . . . . . . . . . . 139

Table 22 Possible common problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

Table 23 Possible H.323 problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Table 24 NPI/TON values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

Table 25 Sample Numbering Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

Table 26 VoIP Transmission Characteristics for unidirectional continuous media stream 154

Table 27 Bandwidth Requirements per Gateway port for half-duplex links . . . . . . . . . . . 156

Table 28 Bandwidth Requirements per Gateway port for Full-duplex links . . . . . . . . . . . 157

Table 29 Link capacity example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

Table 30 Norstar VoIP Gateway Product Interoperability Summary . . . . . . . . . . . . . . . . 175

Table 31 Site pairs and routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Table 32 Computed load of voice traffic per link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

Table 33 Delay and error statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190

Table 34 VoIP Gateway functional specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

Table 35 Default RTP/RTCP/T.38 port allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

Table 36 Industry standard packet types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209

Table 37 VoIP Gateway specific payload types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210

Norstar VoIP Gateway Configuration Guide

12 Tables

P0606298 02

Preface

The Norstar VoIP Gateway is an accessory for Norstar KSU that provides up to four IP telephony trunks. These IP telephony trunks allow you to establish voice calls to other IP telephony enabled telephones systems using a data networking connection. Examples of IP telephony enabled telephone systems are a Business Communications Manager system, Meridian 1 IPT or another Norstar KSU equipped with a Norstar VoIP Gateway.

Before you begin

This guide provides information about the configuration and operation of the Norstar VoIP Gateway. It is intended for persons responsible for the configuration of a Norstar VoIP Gateway system. Prior knowledge of IP networks is required.

Before using this guide, the Norstar VoIP Gateway must be connected to the Norstar KSU.

This guide assumes:

• You have planned the telephony and data requirements for your Norstar system.

• The Norstar KSU is installed and initialized, and the hardware is working. External lines and internal telephones and telephony equipment are connected to the KSU or Expansion Modules.

• Configuration of lines is complete.

• Operators have a working knowledge of the Windows operating system and of graphical user interfaces.

• Operators who manage the data portion of the system are familiar with network management and applications.

Symbols used in this guide

This guide uses these symbols to draw your attention to important information:

Caution: Caution Symbol Alerts you to conditions where you can damage the equipment.

Danger: Electrical Shock Hazard Symbol Alerts you to conditions where you can get an electrical shock.

Warning: Warning Symbol Alerts you to conditions where you can cause the system to fail or work improperly.

Norstar VoIP Gateway Configuration Guide

14 Text conventions

Note: Note/Tip symbol

Alerts you to important information.

Tip: Note/Tip symbol Alerts you to additional information that can help you perform a task.

Text conventions

This guide uses these following text conventions:

angle brackets (< >) Represent the text you enter based on the description inside the

brackets. Do not type the brackets when entering the command. Example: If the command syntax is

ping

<ip_address>

, you enter: ping 192.32.10.12

bold Courier text

italic text Represents terms, book titles and variables in command syntax

bold text Represents fields names, field entries, and screen names in the

plain Courier text

dollar sign ($)

Acronyms

This guide uses the following acronyms:

Represent command names, options and text that you need to enter. Example: Use the Example: Enter

dinfo command.

show ip {alerts|routes}.

descriptions. If a variable is two or more words, the words are connected by an underscore.

Example: The command syntax

show at

valid_route

<valid_route>

is one variable and you substitute one value for it.

configuration application. Represents command syntax and system output, such as prompts and

system messages. Example:

The $ symbol indicates hexadecimal notation.

Set Trap Monitor Filters

ATM Asynchronous Transfer Mode CDP Coordinated Dialing Plan CLID Calling Line Identification CIR Committed Information Rate CNG Comfort Noise Generation ECM Error Correction Mode

P0606298 02

Related publications 15

ICMP Internet Control Message Protocol IEEE802 ESS Institute of Electrical and Electronics Engineers, Inc., standard 802

Electronic Switching System Identification code IP Internet Protocol ISDN Integrated Services Digital Network LAN Local Area Network LATA Local Area and Transport Area MCR Maximum Cell Rate MOS Mean Opinion Score PCM Pulse Code Modulation PING Packet InterNet Groper PPP Point-to-Point Protocol PRI Primary Rate Interface PSTN Public Switched Telephone Network QoS Quality of Service RAS Registration, Admissions and Status RTP Real-time Transfer Protocol SNMP Simple Network Management Protocol TCP Transmission Control Protocol UDP User Datagram Protocol UDP Universal Dialing Plan VoIP Voice over Internet Protocol VAD Voice Activity Detection VLAN Virtual LAN WAN Wide Area Network

Related publications

Documents referenced in the Norstar VoIP Gateway Configuration Guide include:

• Norstar Installer Guide

• Norstar System Coordinator Guide

• Norstar VoIP Gateway Installation Guide

Norstar VoIP Gateway Configuration Guide

16 How to get help

How to get help

USA and Canada

Authorized Distributors - ITAS Technical Support

Telephone:

1-800-4NORTEL (1-800-466-7835) If you already have a PIN Code, you can enter Express Routing Code (ERC) 196#. If you do not yet have a PIN Code, or for general questions and first line support, you can enter ERC 338#.

Website:

http://www.nortelnetworks.com/support

Presales Support (CSAN)

Telephone:

1-800-4NORTEL (1-800-466-7835) Use Express Routing Code (ERC) 1063#

EMEA (Europe, Middle East, Africa)

Technical Support - CTAS

Telephone:

00800 800 89009

Fax:

44-191-555-7980

email:

emeahelp@nortelnetworks.com

CALA (Caribbean & Latin America)

Technical Support - CTAS

Telephone: 1-954-858-7777

email:

csrmgmt@nortelnetworks.com

APAC (Asia Pacific)

Technical Support - CTAS

Telephone:

+61 388664627

Fax:

+61 388664644

email:

asia_support@nortelnetworks.com

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Chapter 1 About Norstar VoIP Gateway

The VoIP Gateway provides excellent voice quality and optimized packet voice streaming over IP networks. The product enables voice, fax and data traffic to be sent over the same IP network.

The VoIP Gateway incorporates up to four ports for connection to analog trunk ports on a Norstar KSU or to a fax. These ports supports up to four simultaneous VoIP calls.

Additionally, the VoIP Gateway is equipped with a 10/100 Base-T Ethernet port for connection to the LAN.

With the VoIP Gateway you can:

• network your Norstar system to another Norstar system or other Nortel Networks Enterprise communications systems using the IP network

• use your IP network to replace PSTN or other costly private network trunking between locations

• use the capacity of the enterprise data network for voice and avoid costly access and long distance charges.

The VoIP Gateway is a very compact device, designed to be installed on a desk-top, on the wall, or in a 19-inch rack.

The VoIP Gateway supports the H.323 ITU protocol, enabling the deployment of "voice over packet" solutions in environments where each enterprise location is provided with a simple Media Gateway. This provides the enterprise with the ability to transmit the voice and telephony signals over a packet network.

The layout diagram, Figure 2 on page 18, illustrates a typical VoIP Gateway application.

Figure 1 Norstar VoIP Gateway front panel

1 2 3 4

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Data

Control

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VoIP Gateway

Norstar VoIP Gateway Configuration Guide

Figure 2 Typical VoIP Gateway application

VoIP Gateway

Router

Branch Office

Modular ICS

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tro

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VoIP Gateway

Branch Office

Compact ICS

Internet

Head Office

Modular ICS

tro

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VoIP Gateway

Router

VoIP Gateway

1 2 3 4

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VoIP Gateway

Router

VoIP Gateway key features

• high quality voice, data and fax over IP networks

• supports up to 4 analog telephone loop start ports

• connected to the IP network via a 10/100 Base-T Ethernet interface

• codecs include: G.711, G.723.1, G.729A

• T.38 Fax with superior performance (can handle a round trip delay up to 9 sec.)

• compliant with H.323 (Version 4)

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• Emergency Line, connected to the unused pins on port #4, with a relay to an analog line, even if the VoIP Gateway is powered off.

• LEDs on the front and rear panels that provide information on the operating status of the VoIP Gateway and the network interface

• Restart button on the front panel that restarts the VoIP Gateway

• compact, rugged enclosure only one-half of a 19-inch rack unit, 1 U high (1.75" or 44.5 mm)

• mounting option of installing two VoIP Gateway in a single 19-inch rack shelf, one U high (1.75" or 44.5 mm).

Supported H.323 features

The VoIP Gateway implements the RadVision™ H.323 version 4.0 protocol stack. In this version, the VoIP Gateway features the following:

Gatekeeper

• Works without a Gatekeeper using the internal phone table.

• Registers to a known Gatekeeper.

• Supports Gatekeeper registration with prefixes

• Functions as an H.323 gateway or can imitate an H.323 terminal with up to four aliases.

• Uses routed-mode calls.

• Uses direct-mode calls.

• Uses redundant Gatekeepers if a redundant Gatekeeper is defined.

• Can fallback to internal routing table if there is no communication with the Gatekeeper.

• Supports the "TimeToLive" parameter. The VoIP Gateway sends Registration requests up to "TimeToLive" expiration.

• Supports IRR messages for KeepAlive.

• Supports the mapping of destination (Alias) numbers in the ACF message by the Gatekeeper.

• Supports RAI (Resource Available Indication) messages, informing gatekeeper that the gateway resources are below a threshold.

Call setup

• Can use the Normal Connect procedure.

• Can use the Fast Connect procedure with or without immediately opening a H.245 channel.

• Can use Tunneling.

• Can negotiate a codec from a list of given codecs for Normal or Fast Connect procedures.

• Can open a H.245 channel when using Fast Connect.

Norstar VoIP Gateway Configuration Guide

Other:

• Supports using a Country Code (0xB5) and Manufacturers Code (0x28) in H.323 messages

• Supports H.323 Annex D, T.38 real time FAX.

• Supports H.450 Call Hold, Call Transfer and Call Forwarding supplementary services (H.450.1, H.450.2, H.450.3 and H.450.4).

• Supports the following codecs: G.711 A-law, G.711 µ-law, G.723.1 (6.3 kbps, 5.3 kbps), G.729.

• Supports DTMF and HookFlash signal out of band using the H.245 channel (using the "Alphanumeric" field).

• Supports DTMF out of band using H.225/Q.931 keypad facility messages.

• Supports of one or two stage dialing for network to VoIP Gateway calls.

• Supports reopening of logical channel and implementation of empty terminal capability set.

• Supports configurable H.323 Port Range.

• Supports H.225/Q.931 Progress Indicator parameter for Fast Connect, enabling playing of local ringback tone or to cut through the voice channel to listen to remote call progress tones/ messages.

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Chapter 2 IP Telephony overview

This section provides a brief overview of the “Key IP telephony concepts”. It also provides a

“Prerequisites checklist” to help you set up your IP Telephony network.

Key IP telephony concepts

In traditional telephony, the voice path between two telephones is circuit switched. This means that the analog or digital connection between the two telephones is dedicated to the call. The voice quality is usually excellent, since there is no other signal to interfere.

In IP telephony, the VoIP Gateway encodes the speech of the call into small data packets called frames. The system sends the frames across the IP network to the other VoIP Gateway, where the frames are decoded and sent to the receiving telephone. If some of the frames get lost while in transit, or are delayed too long, the receiving telephone experiences poor voice quality. On a properly-configured network, voice quality should be consistent for all IP calls.

The following sections describe some of the components for IP telephony:

• “VoIP trunks” on page 21

• “Gatekeepers” on page 22

• “Codecs” on page 22

• “Jitter Buffer” on page 23

• “QoS routing” on page 24

VoIP trunks

VoIP trunks allow voice signals to travel across IP networks. The VoIP Gateway converts the voice signal into IP packets, which are then transmitted through the IP network to a gateway on the remote system. The device at the other end reassembles the packets into a voice signal. Business Communications Manager and Meridian 1 IPT are devices that can use the H.323 protocol trunks which the VoIP Gateway supports.

VoIP trunks and analog/digital telephones

While analog and digital telephones cannot be connected to the VoIP Gateway system with an IP connection, they can make and receive calls to and from other systems through VoIP trunks. Calls received through the VoIP trunks to system telephones are received through the LAN or WAN and are translated within the VoIP Gateway to voice channels.

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22 Key IP telephony concepts

Gatekeepers

A gatekeeper tracks IP addresses of specified devices, and provides authorization for making and accepting calls for these devices. A gatekeeper is not required as part of the network to which your VoIP Gateway is attached, but Gatekeepers can be useful on networks with a large number of devices.

Note: The VoIP Gateway does not contain a gatekeeper application. If you want to put a gatekeeper on your network, it must be put on a separate gatekeeper server. The VoIP Gateway is compatible with RadVision and CSE 1000 gatekeepers.

Codecs

The algorithm used to compress and decompress voice is embedded in a software entity called a codec (COde-DECode).

Two popular Codecs are G.711 and G.729. The G.711 Codec samples voice at 64 kilobits per second (kbps) while G.729 samples at a far lower rate of 8 kbps. For actual bandwidth requirements, refer to “Determining the bandwidth requirements” on page 153, where you will note that the actual kbps requirements are slightly higher than the label suggests.

Voice quality is better when using a G.711 CODEC, but more network bandwidth is used to exchange the voice frames between the telephones.

If you experience poor voice quality, and suspect it is due to heavy network traffic, you can get better voice quality by configuring the IP telephone to use a G.729 CODEC.

The VoIP Gateway supports these codecs:

•G.729

•G.723

•G.711-uLaw

•G.711-aLaw

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Key IP telephony concepts 23

Jitter Buffer

Voice frames are transmitted at a fixed rate, because the time interval between frames is constant. If the frames arrive at the other end at the same rate, voice quality is perceived as good. In many cases, however, some frames can arrive slightly faster or slower than the other frames. This is called jitter, and degrades the perceived voice quality. To minimize this problem, the VoIP Gateway uses a jitter buffer for arriving frames.

The Norstar VoIP Gateway uses a dynamic jitter buffer that can be configured using two parameters:

• Minimum delay (0 msec to 150 msec). This defines the starting jitter capacity of the buffer. For instance, at 0 msec, there is no buffering at the start. At the default level of 70 msec, the VoIP Gateway will always buffer incoming packets by at least 70 msec worth of voice frames.

• Optimization Factor (0 to 12). This defines how the jitter buffer tracks to changing network conditions. When set at its maximum value of 12, the dynamic buffer will aggressively track changes in delay (based on packet loss statistics) to increase the size of the buffer and then not decay back down. This results in the best packet error performance, but at the cost of extra delay. At the minimum value of 0, the buffer tracks delays only to compensate for clock drift and quickly will decay back to the minimum level. This optimizes the delay performance but at the expense of a higher error rate.

The default settings of 70 msec Minimum delay and 7 Optimization Factor should provide a good compromise between delay and error rate. The jitter buffer "holds" incoming packets for 70 msec before making them available to the codec for decoding into voice. The codec actually "takes" frames from the buffer at regular intervals in order to produce continuous speech. As long as delays in the network do not change (jitter) by more than 70 msec from one packet to the next, there will always be a sample in the buffer for the codec to use. If there is more than 70 msec of delay at any time during the call, the packet is too late. The codec will try to access a frame and will not be able to find one. The codec must produce a voice sample even if a frame is not available. It will actually create a voice sample to use that minimizes the effect of the loss. This loss is then flagged as the buffer being too small. The dynamic algorithm then causes the size of the buffer to increase for the next voice session. The size of the buffer may decrease again if the gateway notices that the buffer is not filling up as much as expected. At no time will the buffer shrink to less than the minimum size configured in the Minimum delay parameter.

This delaying of packets can provide somewhat of a communications challenge, as speech is delayed by the number of frames in the buffer. For one-sided conversations, there are no issues. However, for two-sided conversations, where one party tries to interrupt the other speaking party, it can be annoying. In this second situation, by the time the voice of the interrupter reaches the interruptee, the interruptee has spoken (2*jitter size) frames past the intended point of interruption.

Norstar VoIP Gateway Configuration Guide

24 Prerequisites checklist

QoS routing

To minimize voice jitter over low bandwidth connections, the VoIP Gateway can assign specific DiffServ Marking in the IPv4 header of the IP telephony data packets.

The DiffServ Code point (DSCP) is contained in the second byte of the IPv4 header. DSCP is used by the router to determine how the packets will be separated for Per Hop Behavior (PHB). The DSCP is contained within the DiffServ field, which was known as the ToS field in older versions.

Prerequisites checklist

Before you set up VoIP trunks on the VoIP Gateway, complete the following checklists to ensure that the system is correctly set up. Some questions do not apply to all installations.

This guide contains a number of appendices that explain various aspects of the system directly related to IP telephony functions.

This section includes the following checklists:

• “Network diagram” on page 24

• “Network devices” on page 25

• “Network assessment” on page 25

Network diagram

To aid in installation, a Network Diagram is needed to provide a basic understanding of how the network is configured. Before you install IP functionality, you must have a network diagram that captures all of the information described in the following table.

Table 1 Network diagram prerequisites

Prerequisites Yes

1.a Has a network diagram been developed?

1.b Does the network diagram contain any routers, switches or bridges with corresponding IP addresses and bandwidth values for WAN or LAN links?

1.c Does the network diagram contain IP Addresses, netmasks, and network locations of all Norstar VoIP Gateways?

1.d Does the network diagram contain IP Addresses and netmasks of any other IP Telephony gateways that you need to connect to?

1.e Does the network diagram contain the IP address for any Gatekeeper that may be used?

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Network assessment 25

Network devices

The following table contains questions about devices on the network such as firewalls, NAT devices, and DHCP servers.

• If the network uses public IP addresses, complete 2.c.

• If the network uses private IP addresses, complete 2.d. to 2.e.

Table 2 Network device checklist

Prerequisites Yes No

2.a Is the network using DHCP?

2.b Is the network using private IP addresses?

2.c Do you have a public IP addresses for the Norstar VoIP Gateway?

2.d Does the system have a firewall/NAT device?

2.e A hub-based core will not have suitable performance for IP Telephony. Does the network use a non-hub solution at its core?

Network assessment

The following table of questions are meant to ensure that the network is capable of handling IP telephony, and that existing network services are not adversely affected.

Table 3 Network assessment

Prerequisites Yes No

3.a Has a network assessment been completed?

3.b Has the number of switch/hub ports available and used in the LAN infrastructure been calculated?

3.c Does the switch use VLANs? If so, get the VLAN port number and ID.

3.d Have the used and available IP addresses for each LAN segment been calculated?

3.e Has DHCP usage and location been recorded?

3.f Has the speed and configuration of the LAN been calculated?

3.g Has the estimated latency values between network locations been calculated?

3.h Have the Bandwidth/CIR utilization values for all WAN links been calculated?

3.i Has the quality of service availability on the network been calculated?

Norstar VoIP Gateway Configuration Guide

26 Network assessment

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Chapter 3 Configuring the VoIP Gateway

The VoIP Gateway has a web interface you use for gateway configuration, including downloading of configuration files and for run-time monitoring. You can access the web interface from any standard web browser, such as Microsoft™ Internet Explorer or Netscape™ Navigator. Specifically, you can employ this facility to set up the gateway configuration parameters needed to configure the VoIP Gateway. You also have the option to reset the gateway to apply the new set of parameters.

Computer requirements

To use the web interface, you need the following:

• a computer capable of running your web browser

• a network connection to the VoIP Gateway

• one of the following compatible web browsers

• Microsoft™ Internet Explorer™ (version 5.0 and higher)

• Netscape™ Navigator™ (version 7.0 and higher)

Accessing the web interface

To access the web interface:

1 Open your web browser. 2 In the URL field, enter the IP address of the VoIP Gateway.

When you enter the IP address make sure you include http:// at the start of the IP address (for example: http://10.1.10.10. The Enter Network Password screen appears.

Norstar VoIP Gateway Configuration Guide

28 Accessing the web interface

Figure 3 Web browser login screen

3 Enter the User Name and Password.

If you have not changed the user name and password, the default User Name is Admin and the default password is Admin.

Note: Nortel Networks recommends that you change the User Name and Password from their default values. For information about how to change the User Name and Password, refer to “Changing the VoIP Gateway password” on page 133.

4 Click the OK button.

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Configuring the Protocol Definition parameters 29

Configuring the Protocol Definition parameters

To configure the Protocol Definition parameters:

1 Access the web interface. 2 Click the Protocol Management button. 3 Click the Protocol Definition tab.

The Protocol Definition screen appears.

Figure 4 Protocol Definition screen

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30 Configuring the Protocol Definition parameters

4 Configure the Protocol Definition parameters according to the following table.

Table 4 Protocol Definition parameters

Parameter Description

General

Connection Mode Select Fast Start if you want the VoIP Gateway to use the Fast Start connection mode.

Select Normal if you want the VoIP Gateway to use the Normal connection mode. The default value is Fast Start. The Fast Start connection mode allows a media path to be established using H.225,

without having to start the full H.245 protocol session. In some situations, you need to use fast start in order to control call progress tones.

Enable Annex D/T.38 Fax relay

Enable DTMF over H.245 Select Yes to enable DTMF over H.245.

H.323-ID Enter the VoIP Gateway H.323-ID you want to use for registration to the Gatekeeper.

Source Number Encoding Type

Destination Number Encoding Type

Select No to disable Annex D/T.38 Fax relay. Select Yes to enable Annex D/T.38 Fax relay. When you enable this feature, the VoIP Gateway can send and receive Fax messages

using the H.323 Annex D T.38 procedure.

When you enable this feature, the VoIP Gateway sends out of band DTMF signaling using H.245. Out of band signaling is recommended for use with H.323 protocol and the Norstar KSU.

You can enter a string up to 19 characters long. When you are using a Gatekeeper, the VoIP Gateway will send a registration message to

the Gatekeeper with this H323-ID string. Select the source number encoding type. This defines the encoding type of the calling

phone number in H.225 setup messages. You can select E.164, H.323-ID, E.164 & H.323-ID, TableValues or TableValues &

H.323-ID. Select TableValues if you want the VoIP Gateway to use the values configured in the

Tel -> IP Source Number Manipulation table. Select H323-ID if you want the VoIP Gateway to add the H323-ID to the source

information. Select E.164 if you want the VoIP Gateway to use E.164 source encoding and not use the

encoding type defined in the table. The default value is E.164.

Note: If you select an option that includes “H.323-ID”, you must enter a string in the H.323-ID box.

Select the destination number encoding type. This defines the encoding type of the called phone number in H.225 setup messages.

You can select E.164, H.323-ID, E.164 and H.323-ID, or TableValues. Select TableValues if you want the VoIP Gateway to use the values configured in the

Tel -> IP Dest Number manipulation table. Select H.323-ID if you want the VoIP Gateway to add the H323-ID to the destination

information. Select E.164 if you want the VoIP Gateway to use E.164 destination encoding and not use

the encoding type defined in the table. The default value is E.164.

Note: If you select an option that includes “H.323-ID”, you must enter a string in the H.323-ID box.

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+ 190 hidden pages

Nortel VoIP Gateway Configuration Manual

Specifications and Main Features

Frequently Asked Questions

User Manual