MoH Audio Translator question

Unanswered Question
Mar 7th, 2008

We have a CM 4.1(3) cluster which is 6 x subscribers, 1 x publisher, 1 x TFTP server. CallManager service is only running on the subscribers, not on the publisher or TFTP server.

The MoH Audio Translator is not configured on any of the servers yet but needs to be to change the MoH.

It says in the Cisco CallManager Features and Services Guide that you shouldn't do the audio translation on an Active CallManager as it can cause slowdowns or errors. So I thought of using the TFTP server as it is not configured as a CallManager, but if you try to activate the MoH Audio Translator it says you must have the CallManager service active too.

This is contradictory.

Any views?


I have this problem too.
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rob.huffman Fri, 03/07/2008 - 05:44

Hi Stuart,

I wouldn't shy away from firing up the MoH Audio Translator on an active CCM. We have run this way for years without issue. If you want you can pick the "least busy" Sub but don't forget this service is only used during the file conversion process :)

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.

Hope this helps!


scoe Fri, 03/07/2008 - 06:00

Hi Rob,

I understand how it works, I was just a little concerned by the statement

"Caution! If the audio translator translates audio source files on the same server as the

Cisco CallManager, serious problems may occur. The audio translator tries to use all available CPU time, and Cisco CallManager may experience errors or slowdowns. Make sure that audio translation never takes place on an active Cisco CallManager".

But if you've been using the subscriber ok, then that's good enough for me! (I think we'll do the translating out of hours though, just incase).

Thanks for your help,


Jaime Valencia Fri, 03/07/2008 - 10:38

it really depends on the workload of the CUCM server and also in the size of the file and codecs you'll be translating to.

it does cause some high CPU due to the translation process and we always recommend to do this after-hours to avoid any issues.

by "Make sure that audio translation never takes place on an active Cisco CallManager" i believe that they mean not on a server that is currently the call processing engine for a phone.

if you have a 1:1 failover model you can run the service on the server that is the backup server to which no phone should be registered



rob.huffman Fri, 03/07/2008 - 11:03

Hi Stuart,

Sorry man, I didn't include the clip to indicate that you didn't know how it works :) Just to clarify that the service is only used during the actual file translation. My appologies! We always do this after hours (as nicely noted by Jaime) just in case and so you can listed to how it turns out before going live.

Take care,



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