How to detect the IPs of users who are using IM and P2P programs

[Nabeel S. Alzahrani(نبيل الزهراني) <nalzahrani () gosi gov sa>]

Dear All,

Is there any tool/method that allow me to detect the IPs of users who are using IM (Instant Messaging i.e. MSN 
messenger, Yahoo messenger, ICQ, etc) and P2P (Peer-2-Peer programs such Kazaa) in our network?
 
Thanks


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