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4. Link Fault Pass through (LFP)
The LFP function includes the Link Fault Pass Through
function (LLCF/LLR) and the DIP Switch design. LLCF/LLR can
immediately alert administrators about problems with the link
media and provide an efficient solution to monitor the net. The
DIP Switch can disable or enable the LFP function.
With LLCF (Link Loss Carry Forward), when a device connected
to the converter loses the TP line link, the converter’s fiber will
disconnect the link of transmit. With LLR (Link Loss Return),
when a device connected to the converter and loses the fiber
line link, the converter’s fiber will disconnect the link of transmit.
Both can immediately alert administrators about link media
problems and provide an efficient solution to monitor the net.
Link Loss Carry Forward (LLCF)
The FCU-1802Px incorporates an LLCF function for
troubleshooting a remote connection. When LFP function is
enabled, the FL/TP ports do not transmit a link signal until they
receive a link signal from the opposite port.
The diagram below shows a typical network configuration with a
good link status using the FCU-1802Px for remote connectivity.
Media
Converter
Management
Station
Switch/Hub
w/SNMP
Management
Station
Media
Converter
Switch/Hub
w/SNMP
TP
TP
Fiber
Cable
LFP ON
LFP ON
l
LED lit = established link
°
LED unlit = no link
Media
Converter
Management
Station
Switch/Hub
w/SNMP
Management
Station
Media
Converter
Switch/Hub
w/SNMP
TP
TP
Broken
Fiber
Cable
LFP ON
LFP ON
l
LED lit = established link
°
LED unlit = no link
If the connection breaks, the FCU-1802Px link loss forwards
to the switch/hub that generates a trap to the management
