vpacket 5100 Series, 6100 Series Reference Manual

Series 5100/6100

™

Voice/Data Router

Reference Manual

MGCP Telephony

Trademarks and copyrights

All trademarks and registered trademarks listed belong to their respective owners.

Vpacket, Vpacket Communications, and the Vpacket 5100/6100 Series Voice/Data Router are registered trademarks of Vpacket
Communications, Inc., Milpitas, California.

Vpacket Communications, Inc. does not warrant that the hardware will work properly in all environments and applications, and makes no
warranty and representation, either implied or expressed, with respect to the quality, performance, merchantability, or fitness for a particular
purpose.

The products and programs described in this document are licensed products of Vpacket Communications, Inc. This document contains
proprietary information protected by copyright, and this document and all accompanying hardware, software, and documentation are
copyrighted. Vpacket Communications, Inc. has made every effort to ensure that this manual is accurate. However, information in this guide is
subject to change without notice and does not represent a commitment on the part of Vpacket Communications, Inc. Vpacket Communications,
Inc. makes no commitment to update or keep current the information in this document, and reserves the right to make changes to this manual
and/or product without notice. Vpacket Communications, Inc. assumes no responsibility for any inaccuracies and omissions that may be
contained in this document. If you find information in this document that is incorrect, misleading, or incomplete, we would appreciate your
comments and suggestions.

No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying,
recording, or information storage and retrieval systems, for any purpose other than the purchaser's personal use, without the express written
permission of Vpacket Communications, Inc.

Copyright © 2000-2002 by Vpacket Communications, Inc.™ U.S. Patents Pending. All Rights Reserved. Reproduction or media conversion by
any means is protected by copyright and may only occur with prior written permission of Vpacket Communi

cations, Inc.

The PSQM technology included in this product is protected by copyright and by European, US, and other patents, and is provided under license
from OPTICOM Dipl. Ing. M. Keyhl GmbH, Erlangen, Germany, 2001

1390 McCarthy Boulevard
Milpitas, CA 95035

Tel: 1(866)VPACKET (872-2538)
Fax: [phone]
E-mail: [e-mail]
Web: http://www.vpacket.com

Document title Date

issued

Product number Release

Vpacket Series 5100/6100 Voice/Data Router Reference Manual MGCP
Configuration

June 2002 750-0031-001, Rev A 2.1.1

Vpacket 5100/6100 Series Voice/Data Router Reference Manual
(Data Features)

750-0025-001, Rev A

Vpacket 5100/6100 Series Voice/Data Router SIP Telephony Configuration 750-0032-001, Rev A

Vpacket 5100/6100 Series Voice/Data Router H.323 Telephony Configuration 750-0033-001, Rev A

Vpacket 5100/6100 Series Voice/Data Router Web Interface Manual 750-0035-001, Rev A

About this manual

About this manual

ii Vpacket 5100/6100 Series MGCP Telephony

Content summary

Vpacket 5100/6100 Series MGCP Telephony

iii

Audience

This manual is written for the technical staff of a service provider, who are responsible for the
telephony configuration of a Vpacket 5100/6100 Voice/Data Router (VDR). These users include,
but are not limited to, network technicians, systems administrators, and network operation staff.

Content summary

This manual contains all of the information you need to configure a 5100/6100 VDR to operate
within an MGCP environment. Table 1 lists the chapters and appendixes and a summary of each.

Table 1. Chapter summaries

Location Contents

Chapter 1 About MGCP Describes MGCP

Chapter 2 Coding profile
commands

Explains the coding profile commands and gives CLI examples

Chapter 3 TCID commands Explains the TCID commands and gives CLI examples

Chapter 4 MGCP commands Explains the MGCP-related commands and gives CLI examples

Chapter 5 T1 interface
commands

Explains the T1 interface commands

Chapter 6 Voice quality
commands

Explains the voice quality commands

Chapter 7 Default coding
profiles and TCID settings

Lists the default codecs

About this manual

iv Vpacket 5100/6100 Series MGCP Telephony

Conventions

This manual uses typeface, syntax, and messages to alert you to information of special interest.

Typefaces

Table 2 lists the typefaces that are used in this manual.

Command syntax

The syntax of commands is described using the following conventions:

• Angle brackets (<fill_in_the_blank >) denote required parameters or arguments.

• Square brackets ([ ]) denote optional elements.

• A pipe (|) separates choices.

Messages

Notes, cautions, and warnings are posted throughout the manuals to give supplementary
information and encourage safety awareness and safe practices.

Notes

Notes are supplemental information requiring your attention.

For example:

Note. Please remember to go to the Vpacket Web site and complete the online
Warranty Registration Card. Doing so registers your Vpacket 5100/6100 VDR and
allows you to receive the latest information, technical support, and upgrades
applicable to your unit.

Table 2. Typefaces and their meanings

Typefac e Description

Bold Designates menus, commands, and parameters

Courier Designates output resulting from a command issued by a user and messages

issued via a telnet or terminal-emulation screen

Related documentation

Vpacket 5100/6100 Series MGCP Telephony

v

Cautions

Cautions are information requiring extra attention.

For example:

Caution. No system-level confirmation message appears during the deletion.

Warnings

Warnings are information that, if not followed, could result in injury or equipment damage.

For example:

Warning. Use of longer screws could result in damage to internal components.

Related documentation

The documentation set related to the Vpacket 5100/6100 VDR includes all documents on the
CD-ROM that was shipped with the unit:

• Vpacket 5100/6100 Series Voice/Data Router Installer’s Guide, Release 2.1

•Quick Start Guides

• T1 and dual T1 Quick Start Guide

• SDSL Quick Start Guide

• Ethernet WAN Quick Start Guide

• T1-PRI Voice Quick Start Guide

•Vpacket 5100/6100 Series Voice/Data Router Datasheet

The reference manual is broken down into five sections allowing you to print only the sections
that apply to your network environment:

• Vpacket 5100/6100 Series Voice/Data Router Reference Manual (Data Features)

• Vpacket 5100/6100 Series Voice/Data Router MGCP Telephony Configuration

• Vpacket 5100/6100 Series Voice/Data Router SIP Telephony Configuration

• Vpacket 5100/6100 Series Voice/Data Router H.323 Telephony Configuration

!

WARNING

About this manual

vi Vpacket 5100/6100 Series MGCP Telephony

Contact information

For more information about the Vpacket 5100/6100 Series VDRs, please contact us using any of
the following methods.

Voice calls

We welcome your calls at 1(866) 872-2538 (VPACKET) Monday through Friday, from 9:00 am to
6:00 pm Pacific Time. Voice mail is available during non-business hours.

E-mail

If you prefer, you can send information requests to our e-mail address: [e-mail]

Fax number

You can also send your requests for information to our 24-hour fax number:

1(408) 433-5870

Website

Our website contains valuable information about our products. We encourage you to visit us at
http://www.vpacket.com

Contents

Vpacket 5100/6100 Series MGCP Telephony vii

About MGCP 1

MGCP and voice services over IP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Setting up voice ports for MGCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Coding profiles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

TCID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Activating and storing configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Evaluating call quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Accessing MGCP commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Accessing the help feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Viewing the DSP version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Recommended FAX settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Coding profile commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Assigning codecs to coding profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Setting the coding usage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Viewing coding profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Setting the voice information field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Setting the nominal delay (jitter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Setting the maximum delay (jitter). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Setting the adaptive playout function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Setting the DTMF relay mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Setting the VAD mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Setting an audio threshold. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Setting the silence detect time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Setting a silence detection level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Setting tone detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Enabling or disabling the echo canceller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Setting the processor mode for the echo canceller. . . . . . . . . . . . . . . . . . . . . . . 24

Setting the echo canceller tail length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Setting the echo canceller processor value. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Setting the refresh state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Setting the echo canceller refresh coefficient . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

viii Vpacket 5100/6100 Series MGCP Telephony

CONTENTS

TCID commands 27

TCID commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Required TCID commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Assigning a TCID number and coding profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Setting the notify entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Setting the TCID endpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

TCID FXS loopstart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Setting the on hook level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Setting the seize detect parameter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Setting the originator clear detect parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Setting the answer-side clear detect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Miscellaneous TCID parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Setting the TCID mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Setting the receive gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Setting the transmit gain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Setting the idle noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Setting the TCID state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Copying the settings of one TCID to another TCID . . . . . . . . . . . . . . . . . . . . . . . 37

Setting tone out on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Setting tone out off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Setting a call length limit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Setting the default digit map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Setting the default event list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Setting the partial digit timer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Setting the critical digit timer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Setting the type of service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

MGCP commands 43

MGCP commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Enabling T1 CAS for MGCP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Enabling MGCP to interoperate with a Nuera softswitch . . . . . . . . . . . . . . . . . . . 47

Setting the MGCP version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Viewing the MGCP code version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Viewing the current MGCP configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Setting the remote gateway name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Setting the DNS IP address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Enabling all endpoints to send messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Vpacket 5100/6100 Series MGCP Telephony ix

CONTENTS

Enabling or disabling recording of events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Setting the number of transmissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Setting the number of retransmissions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Setting the restart wait time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Setting the nominal wait time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Setting a history limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Setting the initial time-out delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Setting the minimum time delay before a reconnect . . . . . . . . . . . . . . . . . . . . . . 56

Enabling event recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Enabling or disabling keep alive messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Setting the connection type attribute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

T1 interface commands 59

T1 voice interface commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

Viewing the T1 configuration settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Setting the T1 frame mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Setting the T1 line coding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Setting the T1 clock source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Setting the T1 loopback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Voice quality commands 65

Call quality commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67

Enabling the call detail records feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Viewing the call detail record . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Deleting CDR information from the Flash memory. . . . . . . . . . . . . . . . . . . . . . . . 68

Viewing CDR statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Data coding profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

Default settings for TCID 0 and 23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82

x Vpacket 5100/6100 Series MGCP Telephony

CONTENTS

Contents

1

About MGCP

Overview, page 3

MGCP and voice services over IP, page 3

Setting up voice ports for MGCP, page 5

Activating and storing configurations, page 6

Evaluating call quality, page 6

Accessing MGCP commands, page 7

Accessing the help feature, page 7

Viewing the DSP version, page 8

CHAPTER 1

About MGCP

2 Vpacket 5100/6100 Series MGCP Telephony

MGCP and voice services over IP

Vpacket 5100/6100 Series MGCP Telephony 3

Overview

This chapter describes the capability of the 5100/6100 VDR to support IP telephony with the
media gateway control protocol (MGCP) and the commands available to configure the voice
ports using the Command Line Interface (CLI). MGCP is supported for FXS and T1-CAS
5100/6100 VDR models.

Note. If you are using MGCP with a digital T1 port, you need to set the T1 parameters
before setting any coding profile, TCID, or MGCP commands.

This chapter contains the following information:

• Background information about MGCP

• A description of the uses of telecommunication channels (TCIDs) and their coding profiles
for encoding the characteristics of traffic flow

• Procedures for accessing the telephony command shell and help features

MGCP and voice services over IP

The basic conditions that required bringing together data and voice routing capabilities were the
development of specialized telephonic applications connecting LAN devices, across a WAN, and
with interfaces to the PSTN. These required attention to several key areas:

• Operational differences between packet-switched and circuit-switched environments

• Major issues revolving on the management of bandwidth, QoS, and latency

These required the development of protocols capable of managing:

• Audio compression to reduce bandwidth

• Sensitivity to latency on the audio path–a 200ms round trip is considered acceptable

• Use jitter buffers and codecs that minimize the network impacts

MGCP provides the means to interconnect a large number of IP telephony gateways. MGCP
assumes that a call agent (CA) performs the intelligence of all call-control operations and that a
media gateway (MG) carries out all media processing and conversion.

MGCP provides an internetworking control system to control telephony gateways from external
call control elements are referred to as call agents. A telephony gateway is a network element that
provides conversion between the audio signals carried on telephone circuits and data packets
carried over the Internet or over other packet networks.

CHAPTER 1

About MGCP

4 Vpacket 5100/6100 Series MGCP Telephony

Example of gateways are:

• Trunking gateways provide an interface between the telephone network and a Voice over IP
network. Such gateways typically manage a large number of digital circuits.

• Voice over ATM gateways operate much the same way as voice over IP trunking gateways,
except that they interface to an ATM network.

• Residential gateways provide a traditional analog (RJ11) interface to a Voice over IP network.
Examples of residential gateways include cable modem/cable set-top boxes, xDSL devices,
broad-band wireless devices.

• Access gateways provide a traditional analog (RJ11) or digital PBX interface to a Voice over
IP network. These can be access gateways and include small-scale voice over IP gateways.

• Business gateways provide a traditional digital PBX interface or an integrated “soft PBX”
interface to a Voice over IP network.

• Network Access Servers attach a modem to a telephone circuit and provide data access to the
Internet. We expect that, in the future, the same gateways will combine Voice over IP services
and Network Access services.

• Circuit switches or packet switches can offer a control interface to an external call control
element.

MGCP assumes a call control architecture in which the call control “intelligence” is outside the
gateways and handled by external call control elements. The MGCP assumes that these call
control elements, or Call Agents, will synchronize with each other to send coherent commands to
the gateways under their control. MGCP does not define a mechanism for synchronizing Call
Agents. MGCP is, in essence, a master/slave protocol, where the gateways are expected to execute
commands sent by the Call Agents.

MGCP assumes a connection model constructed of endpoints and connections. Endpoints are
sources or sinks of data and could be physical or virtual.

Examples of physical endpoints are:

• An interface on a gateway that terminates a trunk connected to PSTN switch (for example, a
Class 5 or Class 4 switch). A gateway that terminates trunks is called a trunk gateway.

• An interface on a gateway that terminates an analog POTS connection to a phone, key
system, PBX, etc. A gateway that terminates residential POTS lines (to phones) is called a
residential gateway.

• An example of a virtual endpoint is an audio source in an audio-content (media) server.

Creation of physical endpoints requires hardware installation, while creation of virtual endpoints
can be done in software.

Connections may be either point-to-point or multipoint. A point-to-point connection is an
association between two endpoints with the purpose of transmitting data between these
endpoints. Once this association is established for both endpoints, data transfer between these
endpoints can take place.

Setting up voice ports for MGCP

Vpacket 5100/6100 Series MGCP Telephony 5

Setting up voice ports for MGCP

To enable voice services, you must individually set up each voice port. Each voice port needs to
have telephony channel identifier (TCID) parameters configured, a set coding profile and then
any coding profile parameters need to be configured.

Note. Vpacket strongly recommends that you use the supplied coding profiles listed in
Appendix D for initial configuration and system tests. Only when network quality
characteristics have been benchmarked and systematically tested, you can proceed
with customizing them.

Coding profiles

Coding profiles are configuration files that consist of numbered sets of parameters that control
the characteristics of the voice and fax traffic over the DSP channels. You can assign at least one
but usually two coding profiles (one for voice and one for fax) to a TCID as a way of providing
quick definition of services over that channel. Coding profiles setup and coding profile
commands begin on page 12.

Coding profiles can be used by any TCID assigned to a port on a 5100/6100 VDR but only one at
a time.

Vpacket has supplied eight default coding profiles, six for voice and two for fax. Each coding
profile uses one of the major industry standard codecs, including G.711 (A-law 64 kbps), G.711m­law, G.723 5.3, G.723 6.3, G.726 (ADPCM), and G.729ab as well as two versions of T.38 fax.
Based on these coding profiles, you can create additional coding profiles for a maximum of 32
coding profiles. See “Advanced MGCP commands” on page 1 for more information.

When the VDR first boots up, all TCIDs are assigned the default coding profile 0 (G.711m- law).

TCID

The TCID represents the telephony (logical) channel associated with each analog port. They are
numbered as integers from 0 to (the number of voice ports on the VDR minus 1). For example,
the 24-port VDR (either 24 analog FXS ports or 24 channels in T1-CAS) has a TCID range of 0-

23. TCID setup and TCID commands begin on page 29.

CHAPTER 1

About MGCP

6 Vpacket 5100/6100 Series MGCP Telephony

Figure 1-1 shows the 5100/6100 voice ports, voice port numbers, TCID numbers, and coding
profiles.

Figure 1-1. Relationship between voice ports, TCID, and coding profiles

Activating and storing configurations

When a command is issued, it is placed in a temporary storage area where it can be stored or
removed by user operation. To implement a change, that command must be stored in Flash
memory with the activate command and then stored in the configuration file with a commit
command so when the VDR is rebooted it is part of the current configuration. When a sequence
of commands is entered and processed, it changes the values of the affected parameters in a
temporary area, but this does not affect current operation which uses values in the active area.

When you issue the activate command, the new configuration data is moved from the temporary
area to the active area, where it can actually be used. Thus a user can make multiple changes in the
temporary area, for example, using set coding commands, then put them into use with a single
activate command.

Use the activate command only between calls since when it is invoked, it tears down (disrupts)
any calls that are in progress.

Configuration data in the active area is only available while the software platform remains in
operation. If the reset command is issued, or if the platform is manually reset, the active area is
reloaded from the data stored in Flash memory. Data in the active area may be saved to Flash
memory by entering the commit command.

Evaluating call quality

A key feature of the VDR’s support for MGCP is the Call Detail Record (CDR) functionality.
CDR records every successful phone call which is placed through the VDR. Each successful
phone call will have one record in the CDR list. The System Administrator can extract and review
detailed records concerning phone quality and also can access these records for billing purposes.

1

2

3

4

5

6

7

8

9

10

11

12

13

14 15

16

171819 20

21

22 23 24

TCID 0

TCID 23

TCID 11

Coding profile 1

voice

fax

voice

voice

fax

fax

Coding profile 1

Coding profile 1

2

2

2

5100/6100 VDR

voice ports

Accessing MGCP commands

Vpacket 5100/6100 Series MGCP Telephony 7

Accessing MGCP commands

MGCP commands are available within the command line interface (CLI) under the telephony
command shell. Once you establish connectivity to the 5100/6100 VDR either through a
HyperTerminal session or a telnet session, you can access the telephony shell by entering tel and
pressing the Enter key (Figure 1-2).

Figure 1-2. Entering the telephony command shell

Accessing the help feature

Once inside the telephony command shell, you can view a listing of MGCP commands by
entering either the set or show keywords (Figure 1-3).

Figure 1-3. Viewing MGCP help

If you enter a two word combination, you can view the entire list of available commands within
that group. The list contains both basic and advanced commands; so, it is possible to change
parameters that might adversely affect a network.

The commands are listed by group:

• Show commands

• Coding profile parameter command

• TCID parameter commands (including loop start options)

• MGCP parameter commands

• Call quality commands

VPacket# tel
telephony#

VPacket# tel
telephony# set
set tcid
set coding
set xgcp
VPacket#

CHAPTER 1

About MGCP

8 Vpacket 5100/6100 Series MGCP Telephony

Viewing the DSP version

You can view a character string that identifies the DSP software version by issuing the show
dsp_version command.

Syntax: show dsp_version [dsp]

Argument:

dsp the number of the DSP about which you want to view information

Example:

In this example, the DSP information is displayed.

MXP>show dsp_version 1

DSP Version: 6.2.3.107, Voice & Fax, @Small, C548F/C549F, Codecs 0xffd2, Features
0x1fe

Coding profile

commands

Contents

2

Overview, page 11

Recommended FAX settings, page 12

Coding profile commands, page 12

CHAPTER 2

10 Vpacket 5100/6100 Series MGCP Telephony

Vpacket 5100/6100 Series MGCP Telephony 11

Overview

Note. If you are using MGCP with a digital T1 port, you need to set the T1 parameters

before setting any coding profile, TCID, or MGCP commands.

Coding profile commands are used for setting up voice and fax services. These commands allow
you to customize:

• type and usage parameters

• VAD-related parameters

• Echo canceller-related parameters

Voice Activation Detection (VAD) allows a data network carrying voice traffic over the Internet
to detect the absence of audio and conserve bandwidth by preventing the transmission of “silent
packets” over the network. Most conversations include about 50% silence; VAD (also called
“silence suppression”) can be enabled to monitor signals for voice activity so that when silence is
detected for a specified amount of time, the application informs the Packet Voice Protocol and
prevents the encoder output from being transported across the network.

Caution. Before using any MGCP commands, Vpacket strongly recommends that you
prepare a backup configuration of your installation as you have benchmarked it.

Echo canceller commands define the characteristics for controlling voice degradation, adjusting
the filter drift, and managing the echo cancelling features.

Caution. Before using any MGCP commands, Vpacket strongly recommends that you
prepare a backup configuration of your installation as you have benchmarked it.

!

!

CHAPTER 2

12 Vpacket 5100/6100 Series MGCP Telephony

Recommended FAX settings

The recommended fax settings (G.711) for a coding profile are as follows:

• set coding 11 copyof 0

• set coding 11 usage fax on

• set coding 11 usage voice off

• set coding 11 vad off

• set coding 11 nom_delay 80

• set coding 11 max_delay 160

• set coding 11 adaptive_playout off

• set coding 11 tone_detect off

The number 11 (eleven) is a place holder indicating the profile number. You can choose a
different number. In addition to these commands, you also need to assign the fax coding profile to
a TCID (set tcid 0 fax_prof 11) and set the following MGCP command: set xgcp fax_support
local. After the settings are configured, you need to activate and commit the changes.

Coding profile commands

Table 2-1 lists the coding profile commands for an MGCP environment.

Table 2-1. Coding profile commands

Table 2-2.

Command See...

set coding [prof_id] coding_type page 13

set coding [prof_id] usage page 14

show coding page 15

set coding [prof_id] vif page 17

set coding [prof_id] nom_delay page 19

set coding [prof_id] max_delay page 19

set coding [prof_id] adaptive playout page 20

set coding [prof_id] dtmf_relay page 21

Coding profile commands

Vpacket 5100/6100 Series MGCP Telephony 13

Caution. Before using any MGCP commands, Vpacket strongly recommends that
you prepare a backup configuration of your installation as you have benchmarked it.

Some commands that appear in the help should not be altered. The 5100/6100 VDR allows you
to set these some of these parameters, but the choices you configure will not impact the function
of the 5100/6100 VDR because the choices are either not applicable to the 5100/6100 VDR
(some modem or telephone features) or the choices are not yet supported by the system.

One unalterable command exists: set coding [prof_id] ec_cfg <nlp_fix|4w_det>; nlp_fix is the
valid choice; 4w_det is not a valid choice

Unsupported or nonapplicable commands include:

• set coding [prof_id] xfer [g729|g727|pcm|fax]; Frame Relay is not supported

• set coding [prof_id] blocksplit [on|off]; Frame Relay and G.727 are not supported

• set coding [prof_id] enhbits <bits>; G.727 is not supported

• set coding [prof_id] v18_tone_detect [on|off]

• set coding [prof_id] ss7_cot_tone_detect [on|off]

• set coding [prof_id] sf_sig_tone_detect [on|off]

• set coding [prof_id] modem_tx_level <value -- In dB (0 to -13)>

• set coding [prof_id] modem_cd_threshold <0=-26dBm,1=-33dBm, 2=-43dBm>

• set coding [prof_id] modem_cd_threshold <0=-26dBm,1=-33dBm, 2=-43dBm>

Assigning codecs to coding profiles

You can specify the codec type for a coding profile by issuing the set coding command.

Syntax: set coding [prof_id] coding_type [tx|rx] <codec type>

Argument:

tx|rx (optional) choice of transmit (tx) or receive (rx)

codec type Refer to Table 2-3.

Table 2-3. Codec parameter names and descriptions

Codec Type/parameter Description

pcm_mu PCM u-Law coding

pcm_a PCM a-Law coding

a16 ADPCM 16kbps coding

a24 ADPCM 24kbps coding

!

CHAPTER 2

14 Vpacket 5100/6100 Series MGCP Telephony

Example:

In this example, the telephony submenu is accessed and then the coding command is entered. The
5100/6100 VDR responds to confirm the action.

Setting the coding usage

You can set the coding usage by issuing the set coding [prof_id] usage command.

Syntax: set coding [prof_id] usage [voice | fax | modem | data] [on | off]

Arguments:

voice | fax | modem | data

choice of usage

on | off enable or disable usage

Example:

a32 ADPCM 32kbps coding

a40 ADPCM 40kbps coding

g723_53 G.723.1 5.3 kbps coding

g723_63 G.723.1 6.3 kbps coding

g729ab G.729 annex a, annex b 8kbps coding

fax Fax relay

fax_t38 Fax relay in T.38 mode

clear_chan PCM with no other processing (VAD, ECU, etc.)

VPacket# tel
telephony# set coding 1 coding_type pcm_mu
OK
telephony#

VPacket# tel
telephony# set coding 1 usage voice on
OK
telephony#

Table 2-3. Codec parameter names and descriptions

Codec Type/parameter Description

Coding profile commands

Vpacket 5100/6100 Series MGCP Telephony 15

Viewing coding profiles

To view all of the coding profiles, you can issue the show coding command; to view only one,
you can enter a profile number after the command.

Syntax: show coding [prof_ id]

Argument:

prof_id limits the command to showing the requested coding profile

Example:

VPacket# tel
telephony# show coding

Configuration for coding profile id 0:
Tx Coding = G.711 MU
Rx Coding = G.711 MU
Coding profile for voice

Tx VIF size = 640 (bits)
Rx VIF size = 640 (bits)
VAD = ENABLED
VAD threshold = 0 (dB) (relative to ref level of -30dBm)
Playout nominal delay = 30 (msec)
Playout maximum delay = 60 (msec)
Adaptive Playout = ENABLED
Rate = 14400
DTMF Relay = ENABLED
Tone detect = ENABLED
Call Progress Tone detect = DISABLED
V.18 Tone detect = DISABLED
SS7 COT Tone detect = DISABLED
SF Sig Tone detect = DISABLED
EC = ENABLED
EC NL = ENABLED
EC NL Sens = 327
EC Tail = 16 (msec)
EC Refresh = UPDATE
EC Coeffs = RESET
Modem TX level = -13 (dB)
Modem CD threshold = 0
Modem no activity timeout = 20 (sec)
Silence detection time = 60 (msec)
Silence detection level = -50 (dB)
Fax debug level = 0

Caller ID Support = ENABLED

Resampling = DISABLED
EC Config = NLP_FIXED
NLP Confort Noise = 65496

Encapsulation = RTP

CHAPTER 2

16 Vpacket 5100/6100 Series MGCP Telephony

In this example, the coding profile numbered 0 is shown. This profile shows these parameters:

• the transmit coding is set to G.711 Mu

• the receive coding is set to G.711 Mu

• Type of coding profile (in this case, voice)

• the transmit Voice Information Field (VIF) size in bits

• the receive VIF size in bits

•VAD enabled

•VAD threshold

• Playout nominal delay

• Playout maximum delay

• Adaptive playout is enabled

• Rate is set to 14400

• DTMF relay is enabled

• Tone detect is enabled

• Call progress tone detect is disabled

• V.18 is disabled

• SS7 is disabled

• SF signal tone detect is disabled

• Echo canceller (EC) is enabled

• EC NL is enabled

• EC NL sensitivity is set to 327

• EC tail is set to 16 ms

• EC refresh is set to update

• EC coefficients is set to reset

• Modem transmit level is set to -13 dB

• Modem CD threshold is set to zero

• Modem time-out is set to 20 seconds

• Silence detection is set to 60 ms

• Silence detection level is set to -50 dB

• Fax debug level is set to zero

• Caller ID support is enabled

• Resampling is disabled

• EC config is NLP fixed

Coding profile commands

Vpacket 5100/6100 Series MGCP Telephony 17

• NLP comfort noise is 65496

• Encapsulation is set to RTP

Setting the voice information field

You can sets the size (in bits) of the Voice Information Field (VIF) for a coding profile. The
appropriate VIF sizes are related to the coding type. In Table 2-4, a VIF Size value is valid if a
table entry shows the equivalent packet time (in milliseconds); empty entries are not valid.Table 2­5 lists anticipated packet delay as compared to VIF size and codec.

Table 2-4. Voice coding algorithms

VIF

size

in

bits

Voice coding algorithms

G.726 G.729A G.723.1 G.711

16 kbps

3

24 kbps

3

32 kbps

40 kbps

3

8 kbps 5.3 kbps 6.3 kbps 64 kbps

80

5 ms

4

———10 ms———

120 —

5 ms

4

— — — ———

160 10 ms —

5 ms

4

— 20 ms — — —

192—————30 ms30 ms—

200

15 ms

4

——

5 ms

4

— ———

240 — 10 ms — — 30 ms — — —

320 20 ms — 10 ms — 40 ms — — —

360 —

15 ms

4

— — — ———

384—————60 ms60 ms—

400

25 ms

4

— — 10 ms 50 ms — — —

480 30 ms 20 ms

15 ms

4

— 60 ms — — —

560 — — — — 70 ms — — —

600 —

25 ms

4

— 15 ms — — — —

640 — — — 20 ms — — — 10 ms

720 — 30 ms — — — — — —

CHAPTER 2

18 Vpacket 5100/6100 Series MGCP Telephony

Syntax: set coding [prof_id] vif [tx|rx] <vif size in bits>

Argument:

tx|rx (optional) indicates transmit or receive

VIF size in bits See Table 2-3.

Example:

In this example, the VIF is set for 480 bits.

800 — —

25 ms

4

20 ms — — — —

960 — — 30 ms — — — — —

1000 — — —

25 ms

4

— ———

1200 — — — 30 ms — — — —

1280———————20 ms

1920———————30 ms

3= If encapsulation type is RTP, dynamic payload type is required
4= G.726, G.727 VIF sizes5ms, 15ms, 25ms are available only in restricted builds

VPacket# tel
telephony# set coding 1 vif 480
OK
telephony#

Table 2-4. (continued) Voice coding algorithms

VIF

size

in

bits

Voice coding algorithms

G.726 G.729A G.723.1 G.711

16 kbps

3

24 kbps

3

32 kbps

40 kbps

3

8 kbps 5.3 kbps 6.3 kbps 64 kbps