BW Acct is a bandwidth accounting and reporting
application. It is implemented as a C daemon which
manages accounting rules in an iptables/netfilter
firewall on the Linux 2.4/2.6 kernel. Support for
multiple RDBMS is included, and a plugin
architecture is provided for extending BW Acct to
support other databases. BW Acct can provide
accurate accounting of just about any firewall
rule you can imagine.