A port specific to Fibre Channel Arbitrated Loop (FC-AL). An NL_port has the same functional, logical, and message handling capability as a node port (N_port), but connects to an arbitrated loop rather than to a fabric. In some implementations, ports can function either as N_ports or as NL_ports depending on the network to which they are connected. An NL_port must replicate frames and pass them on when in passive loop mode. See also arbitrated loop, Nx_port.