Allied Telesis AT-MCF2012LC/1 - Manual (Page 34)

Chapter 1: Overview
34
Here is an example of how the Smart MissingLink mode
works. Assume that the fiber optic port in a media converter
channel lost its link to its networking device while the
channel was in the Smart MissingLink operating mode. The
mode would respond by pulsing the transmitter on the
twisted pair port of the channel about once a second, and
flashing the port’s Link LED. This would signal that the port
can still establish a link with its networking device and that
the failure originated on the fiber optic port. When the
connection is reestablished on the fiber optic port, the
twisted pair port resumes normal operations so that the two
ports can again forward traffic to each other.
The operating mode functions the same if the failure starts
on the twisted pair port. Here, the mode pulses the
transmitter on the fiber optic port and blinks the port’s Link
LED.
As with the other two channel operating modes, this mode
does not interfere with the flow of network traffic through the
ports of a channel and so can be used during normal
network operations of a media converter channel. However,
you might want to limit its use to diagnosing a link failure,
particularly if the networking devices connected to the ports
are managed devices. This is because the pulsing of the
transmitter on a port and the constantly changing status of a
link could prove problematic for some managed devices.
For example, the device might send a constant stream of
SNMP traps or, if the device is running a spanning tree
protocol, the protocol may become confused as the status
of the device’s link to the media converter constantly
changes.