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About FiberAlert and LinkLoss
McBasic TX/FX comes with the following troubleshooting features:
FX LinkLoss (a.k.a. "Fiber LinkLoss" or "LinkLoss")
TX LinkLoss (a.k.a. "Twisted Pair LinkLoss” or "Reverse LinkLoss”)
FiberAlert (including Pulsing FiberAlert)
LinkLoss and FiberAlert are advanced troubleshooting features that can help you
locate "silent failures" on your network. However, it is vital that you understand
exactly how FiberAlert and LinkLoss work, and how they will react in your network
configuration, before attempting to install the enclosed module(s).
Installing modules without understanding the effects of LinkLoss
and FiberAlert can cause perfectly functioning units to appear
flawed or even dead.
If you are unfamiliar with LinkLoss and FiberAlert, IMC Networks strongly encourages
you to read the following information. Contact IMC Networks technical support at
(800) 624-1070 (U.S. and Canada), +32-16-550880 (Europe) or
for more information/assistance.
Link Integrity
During normal operation, link integrity pulses are transmitted by all point-to-point
Ethernet devices. When an IMC Networks media converter receives valid link pulses,
it knows that the device to which it is connected is up and sending pulses, and that
the copper or fiber cable coming from that device is intact. The appropriate “LINK”
LED is lit to indicate this. The IMC Networks media converter also sends out link
pulses from its copper and fiber transmitters, but normally has no way of knowing
whether the cable to the other device is intact and the link pulses are reaching the
other end. FiberAlert and LinkLoss allow this information to be obtained from the
fiber, even when physical access to a remote device (and its link integrity LED) is not
available. (See below for explanation of features, see page 4 for using the features in
a typical application).
LinkLoss
FX LinkLoss is a troubleshooting feature. When a fault occurs on the fiber segment of
a conversion, FX LinkLoss detects the fault and passes this information to the twisted
pair segment. If a media converter is not receiving a fiber link, FX LinkLoss disables
the transmitter on the media converter's twisted pair port. This results in a loss of link
on the device connected to the twisted pair port.