netraf is a C written, POSIX threads specification compatible (LinuxThreads) set of programs,
allowing to monitor all network traffic routed through the machine it is installed on,
helping administrators in bandwidth shaping and load profiling.
Flexible and easy configuration of logging options, statistics and periodical summaries.
netraf consist of netrafg, netrafd and netrafl.
Technical specifications and user's manuals are available on this site.

Please take a look at Project Introduction and Project Goals.

SourceFORGE.net: Project Info - A Network Analyzer and Traffic Logger