PLANET GST-80X Series - Manual (Page 17)

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4. LINK PASS THROUGH FUNCTION
The LFP function includes the Link Fault Pass Through function (LLCF/LLR) and the DIP Switch design. LLCF/LLR can
immediately alarm administrators the problem of the link media and provide efficient solution to monitor the net. The DIP
Switch provides disable or enable the LFP function.
LLCF (Link Loss Carry Forward) means when a device connected to the converter and the TP line loss the link, the
converter’s fiber will disconnect the link of transmit. LLR (Link Loss Return) means when a device connected to the con-
verter and the fiber line loss the link, the converter’s fiber will disconnect the link of transmit. Both can immediately alarm
administrators the problem of the link media and provide efficient solution to monitor the net.
4.1 Link Loss Carry Forward (LLCF)
The GST-80X modules incorporates default LLCF function for troubleshooting a remote connection; the Fiber/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 GST-80X for remote connectivity.
Management Switch/Hub Media Media Switch/Hub Management
Station w/SNMP Converter Converter w/SNMP Station
● LED lit = established link ○ LED unlit = no link
If the connection breaks, GST-80X that link loss forward to the switch/hub which generates a trap to the management
station. The administrator can then determine the source of the issue.
Management Switch/Hub Media Media Switch/Hub Management
Station w/SNMP Converter Converter w/SNMP Station
● LED lit = established link ○ LED unlit = no link
#
Notice:
The converter is shipped with the default LFP (LLCF/LLR) function disable.. This feature can also be turned on on-purpose.
If you are familiar with the network installation and for diagnostic purpose (i.e. check which end is broken), you can turn it on
and the converter will take effect immediately. Otherwise, please remains it in the default position.
LLCF is ON LLCF is ON
TP Fiber
Cable
TP
LLCF is ON
LLCF is ON
TP Broken
Fiber
TP