2 link loss return (llr) – PLANET IGTP-80xT Series User Manual
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If the connection breaks, IGTP-80xT 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.
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
Note
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.
3.2 Link Loss Return (LLR)
The fiber ports of IGTP-80xT have been designed with an LLR function
for troubleshooting a remote connection. LLR works in conjunction with
LLCF.
When LLR is enabled*, the port’s transmitter shuts down when
its receiver fails to detect a valid receive link. LLR should only be
enabled on one end of the link and is typically enabled on either the
unmanaged or remote device.
The diagram below shows a typical network configuration with a good
link status using IGTP-80xT for remote connectivity. Note that LLR is
enabled as indicated in the diagram.