Allied Telesis AT-MC1008/SP - Manual (Page 21)

AT-MC1008 Series Installation Guide
21
MODE Push Button
The MODE push button is used to toggle between the three operation
modes: Link Test (LT), MissingLink (ML), and Smart MissingLink (SML).
This button is located on the front panel. The button cycles through these
three modes with each push.
To select between the three modes, use a pointed object such as a pen to
depress the push button.
Link Test
The link test is a fast and easy way for you to test the connections
between the media converter ports and the end-nodes that are connected
to the ports. If a network problem occurs, you can perform a link test to
determine which port is experiencing a problem, and so be able to focus
your troubleshooting efforts on the cable or end-node where the problem
resides.
To perform a link test, toggle the MODE selection button until the LT LED
is green. The LINK LEDs for the ports should now be green, indicating
that they were able to establish a link with their end-nodes. If a LINK LED
is off, the port could not establish a link. Refer to “Troubleshooting” on
page 51 for suggestions on how to isolate the problem.
Note
The link test is a normal mode of operation; therefore, performing a
link test does not interfere with a media converter’s ability to pass
network traffic.
MissingLink
The MissingLink feature enables the two ports on the media converter to
pass the “Link” status of their connections to each other. When the media
converter detects a loss of connection to an end-node, the media
converter shuts down the connection to the other port, thus notifying the
end-node that the connection has been lost.
For example, if the twisted pair cable to the 1000Base-T port on the
media converter were to fail, the unit would respond by dropping the link
on the 1000Base-FX fiber optic port. In this way, the media converter
notifies the end-node connected to the fiber optic port that the connection
on the twisted pair port has been lost. If the failure had started with the