11
station. The administrator can then determine the source of the
problem.
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
*Units are shipped with the LFP function disable (OFF).
Link Loss Return (LLR)
The fiber ports of the FCU-1802Px have been designed with an
LLR function for troubleshooting a remote connection. LLR works
in conjunction with LLCF.
When LFP function 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 the FCU-1802Px for remote connectivity.
Note that LLR and LLCF are enabled as indicated in the diagram.
Media
Converter
Management
Station
Switch/Hub
w/SNMP
Station
Media
Converter
Switch/Hub
Fiber
Cable
LFP OFF
LFP ON
l
LED lit = established link
°
LED unlit = no link
Media
Converter
Management
Station
Switch/Hub
w/SNMP
Station
Media
Converter
Management
Switch/Hub
TP
TP
Broken
Fiber
LFP ON
LFP ON
l
LED lit = established link
°
LED unlit = no link
Port 2
Port 1
Link Loss Carried Forward
Link Loss Returned
Link Loss Carried Forward
