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Link Fault Pass-Through
Link Fault Pass-Through (LFPT) is a troubleshooting feature that combines TX and FX
LinkLoss from both the local and remote Managed Media Converter modules. LFPT is
enabled by turning on both FX and TX LinkLoss on both modules. This feature allows either
end of the conversion to detect a link fault occurring at the other end of the media conversion
chain. FiberAlert can also be added to the remote side of the pair to further assist in locating a
fault.
FX+TX LinkLoss
Cable fault with LFPT enabled (FX+TX LL on both modules)
X
X
1
CONNECTED
DEVICE
CONNECTED
DEVICE
HOST
REMOTE
2
3
1.
A cable fault occurs on the remote twisted pair.
2.
TX LinkLoss detects the fault and disables the OPTICS (or UPLINK) port.
3.
FX LinkLoss detects the fiber loss and disables the DATA port.
The link fault is passed through the media conversion and is observed at each end. It acts just
like it would if the devices were directly connected.
Last Gasp
The Managed Media Converter includes a Last Gasp feature, which sends a trap (configured
in iView²) when the power to the module fails.
37
Now the Managed Media Converter is configured to pass only tagged data between the
OPTICS (or UPLINK) and DATA ports. All untagged data is considered management traffic
and is only passed to and from the OPTICS (or UPLINK) port.
ON
S1
1 2 3 4 5 6 7 8 9 0
OPTICS (or UPLINK) port management
DIP switch (3) is set to ON.
Off
Off
On
Port
SNMP
DIP Switch
Settings
DATA:
Tagged Data Only
OPTICS:
Tagged Data
and Untagged
Management
Data