http://i3xi5qxvbrngh3g6o7czwjfxwjzigook7zxzjmgwg5b7xnjcn5hzciad.onion/proposals/251-netflow-padding.html
Background
At the ISP level, this data typically takes the form of Netflow, jFlow,
Netstream, or IPFIX flow records. These records are emitted by gateway
routers in a raw form and then exported (often over plaintext) to a
"collector" that either records them verbatim, or reduces their granularity
further[2].