Cisco Unity

Document ID: 100432

Contents

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
Cisco Unity PBX IP Media Gateway
Problem
Solution
      Change dtmf-relay mode
NetPro Discussion Forums - Featured Conversations
Related Information

Introduction

This document describes how to solve the problem when Cisco Unity does not accept DTMF tones from a PIMG (PBX IP Media Gateway).

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

• Cisco Unity

• Cisco Unity PBX IP Media Gateway (PIMG)

Components Used

The information in this document is based on this software:

• Cisco Unity 4.x

• Cisco Unity PBX IP Media Gateway

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Cisco Unity PBX IP Media Gateway

The Cisco Unity PBX IP Media Gateway products are integration devices designed to offer a high-quality connection between Cisco Unity or Cisco Unity Connection servers and your existing traditional private branch exchange (PBX). The Cisco Unity PBX IP Media Gateway (PIMG) is an 8-port, stackable integration device that emulates a digital or analog phone (station) on the PBX side and uses the Session Initiation Protocol (SIP) in order to connect to the Cisco Unity server over a LAN or WAN.

Problem

Unity does not accept digits (DTMF signals) entered from phones connected to PBX, but you can hear the Unity greeting and other messages.

Solution

PIMG uses SIP in order to connect PBX and Cisco Unity server over a LAN or WAN. Cisco recommends that you use RFC 2833 dtmf-relay mode when the SIP protocol is used between PIMG and Cisco Unity.

Change dtmf-relay mode

In the PIMG configurarion, change the RTP DTMF-relay mode value in the Gateway Advanced tab settings to RFC2833.

This configuration change allows the PIMG to pass DTMF SIP signaling from the PBX to Cisco Unity.

NetPro Discussion Forums - Featured Conversations

Related Information

• Voice Technology Support
• Voice and Unified Communications Product Support
• Recommended Reading: Troubleshooting Cisco IP Telephony
• Technical Support & Documentation - Cisco Systems