netgraph
Graph based kernel networking subsystem of FreeBSD and DragonFly BSD / From Wikipedia, the free encyclopedia
netgraph is the graph based kernel networking subsystem of FreeBSD since 3.4 and DragonFly BSD since the fork from FreeBSD.[1] 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: