Cisco Unified Communications Manager (CallManager)

CallManager Music On Hold Volume Adjustment

Document ID: 68150

Updated: Feb 02, 2006



This document describes the procedure to change the default Music On Hold (MOH) volume level in Cisco CallManager. During the conversion of dropped audio files, the Default MOH Volume Level parameter controls the volume level. The maximum and minimum volume levels are 0 and -48 decibels (dB), respectively.



Cisco recommends that you have knowledge of these topics:

  • Cisco CallManager

  • Cisco MOH Audio Translator

Components Used

The information in this document is based on these software and hardware versions:

  • Cisco CallManager Version 3.x and later

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.


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

Background Information

In order to add an MOH audio source, you need a music file with good quality. MP3 or Waveform Audio (WAV) are the preferred formats. Other formats can cause problems, such as distorted music. The Cisco MOH Audio Translator service converts audio source files into various coder-decoders so that the MOH feature can use them. Cisco CallManager automatically installs this service when you install the Cisco IP Voice Media Streaming application.

The MOH Audio Translator service automatically translates audio files that you place in the input directory. The installation program creates the directory C:\Cisco\DropMOHAudioSourceFilesHere during installation.

After MOH Audio Translator adds an audio file in the input directory, this file is converted to five WAV files and an Extensible Markup Language (XML) file. The files go in the directory C:\ProgramFiles\Cisco\TFTPPath\MOH.

The suffixes for these files are:

  • alaw.wav

  • au

  • g729.wav

  • ulaw.wav

  • wb.wav

  • xml

For example, if the audio file is atest.wav, the converted files are:

  • atest.alaw.wav


  • atest.g729.wav

  • atest.ulaw.wav

  • atest.wb.wav

  • atest.xml

See Figure 1.

Figure 1 – Converted Wav Files


MOH Volume Level

When the Cisco MOH Audio Translator service converts audio source files, the Default MOH Volume Level parameter specifies the MOH volume level in decibels.

Complete these steps to change this parameter:

  1. Select Start > Programs > Cisco CallManager > version number > CallManager Administration.

  2. Click Service in the menu bar and select Service Parameters.

    See Figure 2.

    Figure 2 – Selection of Service Parameters


  3. Select the server name from the Server drop-down list.

    See arrow A in Figure 3.

    Figure 3 – Service Parameters Configuration : 1


  4. Select Cisco MOH Audio Translator from the Service drop-down list.

    See arrow B in Figure 3.

  5. Click the Advanced button above the General Parameters section.

  6. Locate Default MOH Volume Level under the Clusterwide Parameters section.


  7. Set the volume level.

    The default is -24 dB. The minimum and maximum are -48 and 0 dB respectively. Changes to this parameter automatically take effect within 60 seconds.

Changes to this parameter only affect audio files that are processed after the change occurs.

Related Information

Updated: Feb 02, 2006
Document ID: 68150