About Linkloss And Fiberalert - IMC Networks MediaConverter/1 Operation Manual

About LinkLoss and FiberAlert

McPIM TP/FO and McLIM TX/FX and TX/SX include the following features:
• FO/FX LinkLoss (a.k.a. "Fiber LinkLoss" or "LinkLoss")
• TP/TX LinkLoss (a.k.a. "Twisted Pair LinkLoss" or "Reverse LinkLoss")
• FiberAlert and Pulsing FiberAlert
FiberAlert and LinkLoss 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 FiberAlert and LinkLoss can
cause perfectly functioning units to appear flawed or even dead.
About 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 "LNK"
(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. The combination of
FiberAlert and LinkLoss allows this information to be obtained, even when physical
access to a remote device (and its link integrity LED) is not available.
What is FO/FX Link Loss?
FO/FX LinkLoss is a troubleshooting feature. When a fault occurs on the fiber
segment of a conversion, FO/FX LinkLoss detects the fault and passes this information
to the twisted pair segment. If a media converter is not receiving a fiber link, FO/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.
** WARNING **
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