Hello,
This is from the CME CLI Admin Guide: Configuring Music on Hold
http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/admin/configuration/guide/cmemoh.html
MOH file buffer size must be larger than the MOH file (size) that needs to be cached.
You can configure a max file buffer size (per file) anywhere between 64 KB (8 seconds) to 10000 KB (approximately 20 minutes), Default moh-file-buffer size is 64 KB (8 seconds).
Note A large buffer size is desirable to cache the largest MOH file and a better system performance.
From that you can take that the maximum file size should be no larger than 10000 KB.
I've found some other posts that suggest there is no file size and another that states it is recommended to have the file less than 500Kb. You are also bound by the size of the compact flash on the UC, which is 256Mb. Space on the compact flash is also utilized for the IOS, phone loads, locale, and support files.
https://supportforums.cisco.com/message/3088035#3088035
https://supportforums.cisco.com/thread/282667
Some of my colleagues have also suggested that the file be no larger than 1Mb.
Another way around any size limits, is to use the external MoH port.
Also, it sounds like you need to configure your audio file in the right format, because it would be a really long audio file at that size in the correct format
A music file must be in stored in the router's flash memory. This file should be in G.711 format. The file can be in .au or .wav file format, but the file format must contain 8-bit 8-kHz data; for example, ITU-T A-law or mu-law data format.
Here is another thread that shows how to convert the audio file to the correct format: https://supportforums.cisco.com/thread/2112263
Hope this helps.
Thanks,
-john
