QoF (Quality of Flow) is a YAF-derived flowmeter, designed for passive measurement of per-flow performance characteristics. It forked as of YAF version 2.3.2. It removes all payload inspection and packet handling features from YAF, and adds performance measurement and flow pseudonymization features.

QoF is primarily intended to support research into efficient performance metrics for TCP flows; however, it can also be used for general flow measurement, especially in environments where the deployment of technologies which inspect packet payload is restricted. If what you're looking for is a full-featured enhanced flow meter for security applications, stop reading now and go download the latest version of YAF, instead.

The present (github master) revision of QoF has not been significantly changed from YAF aside from the removal of payload inspection and the addition of initial performance measurement and flow pseudonymization. In particular, the documentation is still that shipped with YAF 2.3.2; until the initial alpha release of QoF you'll have to read the code to see what's new.

We intend to track bugfixes in YAF releases subsequent to 2.3.2, but not new features, especially as new YAF features will likely involve DPI features removed from QoF. QoF is still mostly command-line compatible with YAF, but this will probably change in the future, as well.

QoF is licensed under the GNU General Public License, Version 2.