Blocking Napster

Do any of you know wich TCP napster uses. Some of my users are taking up our all of our T'1.

Thanks

SJ

I know at our work we have blocked port 6667 which is Napsters default port if I remember correctly. The only problem with this is that you can go in and change the port that it uses. So far it has worked with a lot of the business that didn't want their employees using it.

Thanks I will give it a try.