[1] Previously many data network operators were relying on Cisco Systems' proprietary NetFlow technology for traffic flow information export.
Using IPFIX, devices like routers can inform a central monitoring station about their view of a potentially larger network.
The sender is also free to use user-defined data types in its messages, so the protocol is freely extensible and can adapt to different scenarios.
When IPFIX is sent over a protocol which keeps a session state (TCP or SCTP), the Template Set need not be retransmitted since it is buffered in Collectors.
Since the Template Set can change over time, it must be retransmitted if a new session state is established or if IPFIX is sent over UDP which is a session-less protocol.