Need help on a thesis work related to IDS/IPS systems …

Hi Techrepublic,

I am Mohan and I am preparing a thesis on flow-based and payload based network intrusion systems using 1999 DARPA data set. My question is the concept of flow-based is really amazing but what are the available systems/applications/technologies ? in this area currently ?. For payload analysis I’ve chosen none other than Snort. For flow based I’ve came across Bro-Ids, Argus … Are they good ?? or is there any other ?? which I missed ?? … Please help me out of this …