iTunes killing bandwidth

[nopixies]

I have been looking for this answer and I have had no luck ---

I know this is unpopular to some, but I need a way to limit or stop iTunes sharing traffic in the office. We have 35 macs and they are sharing iTunes play lists and services which is absolutely killing the internal bandwidth. We need this for the 3D rendering we do and the VOIP services.

We do not mind the local use by the user and encourage it to be used. We have turned off the itunes sharing but it just gets turned back on over a few weeks time. I need to turn off the sharing ports without killing other services and I need to do it without the user being able to over ride it in iTunes. Ideas appreciated...

thanks a billion