Audio File Settings?

Does anyone have experience working with audio files in courses that are presented through an LMS (SumTotal) over a global network?

We are seeing some unusual behavior with courses with audio files in some locations:

- The audio stops buffering and the course freezes

- The progress bar (audio playback control bar) first appears blank and once the audio loads a grey bar appears along with the time and %completed.

Can someone advise on the best ways to ensure that large Flash audio files can be downloaded through a global network. Also is there some way to test whether the issues is with the course or the network?

Any help is greatly appreciated.

Thanks,

Peter