Bayesian IDS

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..