Brocade Communications Tata Communications The demands on the networking infrastructure and thus the switch/router bandwidths are growing exponentially; the drivers are bandwidth hungry rich media applications, inter data center communications etc. Using sampling techniques, for a given sampling rate, the amount of samples that need to be processed is increasing exponentially especially for applications like security threat detection. This draft elaborates on flow-state dependent packet selection techniques and the relevant information models. It describes how these techniques can be effectively used to reduce the number of samples for applications like security threat detection.