ISCXFlowMeter is a network traffic flow generator available from here . It can be used to generate bidirectional flows, where the first packet determines the forward (source to destination) and backward (destination to source) directions, hence the statistical time-related features can be calculated separately in the forward and backward directions. Additional functionalities include, selecting features from the list of existing features, adding new features, and controlling the duration of flow timeout.
NOTE: TCP flows are usually terminated upon connection teardown (by FIN packet) while UDP flows are terminated by a flow timeout. The flow timeout value can be assigned arbitrarily by the individual scheme e.g., 600 seconds for both TCP and UDP.
For citation in your works and also understanding ISCXFlowMeter completely, you can find below published paper: Gerard Drapper Gil, Arash Habibi Lashkari, Mohammad Mamun, Ali A. Ghorbani, "Characterization of Encrypted and VPN Traffic Using Time-Related Features", In Proceedings of the 2nd International Conference on Information Systems Security and Privacy(ICISSP 2016) , pages 407-414, Rome , Italy