Unanswered Question
Oct 15th, 2008


Got the MOH file from the customer, they convert is to G711u in .wav then in .au files format.

When We put it in production (SRST sending the feed to the phone in a remote site). The Music quality is VERY bad, crispy.

Like if CCM was requesting the phone to connect to a G729 device, and MOH send out G711u.

With the Cisco sample file, the quality is good.

The file is 40Mb on a USB key attached to the 2811 Router.

Is the size an Issue ?

Another test, using the .wav format make the music play correctly but this was VERY slow, like 2 times slower than normal.

Is the usage of USB Flash can be my root cause ?


I have this problem too.
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allan.thomas Wed, 10/15/2008 - 07:57

If the quality of the on the router flash is good and the audio file on the USB flash is poor, then I would agree with you.

However, it could be the fact that the audio file was not converted correctly. A similar test would be to copy the file on the USB and see the difference?



5mgagnon Wed, 10/15/2008 - 09:27

I forgot to mention, the Cisco sample file is on the usbflash too.


allan.thomas Wed, 10/15/2008 - 09:39

If that is the case, then I suspect that it is possibly the format of the audio file which is question?

The recommended format for audio source files includes the following specifications:

•16-bit PCM wav file

•Stereo or mono

•Sample rates of 48 kHz, 32 kHz, 16 kHz, or 8 kHz

• 16-bit PCM (stereo or mono) (16k Hz or 32k Hz or 48k Hz or 8k Hz or 44.1k Hz sample rate)

• 8-bit CCITT g.711 a-law or mu-law (stereo or mono) (8k Hz sample rate)



Chris Deren Wed, 10/15/2008 - 19:54

So, are you streaming the file from Flash of the router or multicasting from CM server? Perhaps it's not streaming from flash and instead you are playing G729 MOH which will sound horrible.


allan.thomas Thu, 10/16/2008 - 10:04

Have you had the opportunity to convert the file following the specificiations I mentioned in an earlier post?


5mgagnon Thu, 10/16/2008 - 12:56

Hi, not yet, I got the Source from the customer this after-noon, But i was busy on troubleshooting something else.

daisuketanabe Thu, 12/18/2008 - 10:10

has this problem been solved, yet?

I had a very similar problem on using cusotm Moh file in CCME.

I had used wav file converted by windows sound recorder, and the quality of the sound was awful.

Initially I followed the documentaion from Cisco CME Administration guide, but that didn't work.

Then I used Adobe Audition to convert original Wav file specifications to the following:

Sampling Rate : 8kHz

Channels: Mono

Bit length: 16

Then saved audio file as au with mulaw-8bit.

Finally uploaded the audio file to CME router.

Now sound quality is very good and the data compression is good, too. 14.6Mb for 30mins Moh file isn't too bad.

Hope this helps others who are having same problem.


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