Wikipedia
Netgraph
netgraph is the graph based kernel networking subsystem of FreeBSD. Netgraph provides support for L2TP, PPTP, ATM, bluetooth using a modular set of nodes that are the graph.
Netgraph has also been ported on other Operating Systems:
- NetBSD kernel 1.5V (not integrated into mainline kernel)
- Linux kernel 2.4 and 2.6 by 6WIND (Commercial closed source port)
- Linux kernel 3.0 by LANA