Bayesian IDS...help

Hi there,
 
    I am working on Anomaly based Network IDS...
    Statistical based technique is simple but not quite effective in real scenario...
    I understand Bayesian classifier/Network is  more effective in the context of anomaly detection,
    but i have very little idea about Bayesian approach for IDS...
    Can someone please help me out, i want to know  how to go about it and if there are any open source
    anomaly based tool available (bayesian IDS) ...

Thanks in advance..