i have a hba adapter,and i command systool,it shows :
#systool -c fc_remote_ports -v -d
Class = "fc_remote_ports"

Class Device = "0-0"
Class Device path = "/sys/class/fc_remote_ports/rport-6:0-0"
dev_loss_tmo = "60"
fast_io_fail_tmo = "off"
maxframe_size = "2112 bytes"
node_name = "0x2001000decf52901"
port_id = "0xfffffe"
port_name = "0x2003000decf52900"
port_state = "Online"
roles = "Fabric Port"
scsi_target_id = "-1"
supported_classes = "Class 2, Class 3"
uevent = <store method only>

Device = "rport-6:0-0"
Device path = "/sys/devices/pci0000:05/0000:05:00.0/0000:06:00.0/host6/rport-6:0-0"
uevent = <store method only>


Class Device = "0-1"
Class Device path = "/sys/class/fc_remote_ports/rport-6:0-1"
dev_loss_tmo = "60"
fast_io_fail_tmo = "off"
maxframe_size = "2048 bytes"
node_name = "0x2001000decf52901"
port_id = "0xfffffc"
port_name = "0x250d000decf52900"
port_state = "Online"
roles = "Directory Server"
scsi_target_id = "-1"
supported_classes = "Class 2, Class 3"
uevent = <store method only>

Device = "rport-6:0-1"
Device path = "/sys/devices/pci0000:05/0000:05:00.0/0000:06:00.0/host6/rport-6:0-1"
uevent = <store method only>


Class Device = "0-2"
Class Device path = "/sys/class/fc_remote_ports/rport-6:0-2"
dev_loss_tmo = "30"
fast_io_fail_tmo = "off"
maxframe_size = "2048 bytes"
node_name = "0x50060e80056dc807"
port_id = "0x140000"
port_name = "0x50060e80056dc807"
port_state = "Online"
roles = "FCP Target"
scsi_target_id = "0"
supported_classes = "Class 3"
uevent = <store method only>

Device = "rport-6:0-2"
Device path = "/sys/devices/pci0000:05/0000:05:00.0/0000:06:00.0/host6/rport-6:0-2"
uevent = <store method only>

and i want to know the roles of "Fabric Port","FCP Target",and "Directory Server" means ,and could some one give me some document about the command systool?
thank you