GCR2000xx User Manual
Alloy Computer Products Pty Ltd Copyright ©2010
6. Link Fault Pass Through
LFP is a function used to diagnose link fault issues between your copper and fibre devices.
Two methods are supported, FEF (Far End Fault) and Forced Mode. FEF is used when both
devices support this feature, such as two GCR2000’s. If the copper port on one of the media
converter loses link, a FEF packet is sent to the device at the other end of the fibre. This
device then shuts down the link on the copper and fibre ports of the media converter. If the
connecting fibre device does not support FEF it will not know what the FEF fault packet is
and keep the link active.
Forced mode is used when the second fibre device being used doesn’t support FEF, such as a
fibre switch. If the copper port on the media converter loses link the media converter will
automatically shut down the fibre port on the media converter, this in turn brings down the
fibre link on the connecting switch.
Fig. 3 Normal status via LFP converter
LFP
LFP
GbE
Switch
GbE
Switch
Remote
Station
A
Fibre
Cable
TP
B
C
D
TP
LFP
LFP
GbE
Switch
GbE
Switch
Remote
Station
A
Fibre
Cable
TP
B
C
D
TP
Fig. 4 The status as TP Cable A or D is broken
LFP
LFP
GbE
Switch
GbE
Switch
Remote
Station
A
Fibre
Cable
TP
B
C
D
TP
Fig. 5 The status as Fibre Cable B or C is broken
LFP
GbE Fibre
Switch
GbE
Switch
Remote
Station
A
Fibre
Cable
TP
B
C
Fig. 6 Normal status via LFP converter
LFP
GbE Fibre
Switch
GbE
Switch
Remote
Station
A
Fibre
Cable
TP
B
C
Fig. 7 The status as TP Cable A is broken
