Installation Guide

4030542 Rev B 25
Auto-Negotiation, Duplex Mode, and Speed
CAUTION:
The FiberAlert and LinkLoss features cause data interruptions designed to alert
remote sites of line failures. These data interruptions can be misinterpreted as
module failures when these features are enabled. Enable these features only
when the resulting data interruptions and causes are well understood.
FX LinkLoss
FX LinkLoss is link integrity monitoring feature that forwards fiber link faults to the
RJ-45 DATA port to indicate that a fiber link fault has occurred.
TX LinkLoss
TX LinkLoss is a link integrity monitoring feature that forwards an RJ-45 link fault to
the fiber connected device to indicate that a link fault has occurred.
FiberAlert
FiberAlert minimizes the problems associated with the loss of one strand of fiber.
Normally when a single strand of fiber is lost, the transmitting side of the connection
is unaware that there is a fault. FiberAlert returns faults back on the fiber they came
in on.
Using LinkLoss and FiberAlert
In a typical central site to remote site media conversion, it is recommended that you
enable the LinkLoss and FiberAlert features as indicated in the following:
Feature Enabled Fault Location Port Affected
FiberAlert Remote side only Fiber Fiber
TX LinkLoss Remote side (or both) Twisted pair Fiber
FX LinkLoss Hot side (or both) Fiber Twisted pair
CAUTION:
Do not enable FiberAlert on both modules when using them in pairs. This will
cause them to lock up when a fault occurs on the fiber. Only enable FiberAlert
on the remote module.
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 modules. You enable LFPT by turning
on both FX and TX LinkLoss on both modules.