PLANET FTP-802 - Manual (Page 12)

11
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 FTP-80X 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 FTP-80X 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