Allied Telesis PowerBlade PBC18 - Manual (Page 7)

PN 613-50381-00 Rev A 7 Allied Telesyn, Inc.
Mode Selection 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 be able
to focus your troubleshooting efforts on the cable and end-node where
the problem resides.
A link test is performed when the Mode Selection button is toggled until
the LT LED is green. For instructions on performing a link test, refer to
“Troubleshooting” in the PowerBlade PBC18 Installation Guide.
Note
Performing a link test does not interfere with a media converter’s
ability to pass network traffic.
MissingLink
The MissingLink feature enables the ports on the media converter to
pass the “Link” status of their connections to each other. When the
media converter detects a problem with one of the ports, such as the
loss of connection to a 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 network twisted pair cable on a AT-PB1005G were to
fail, the module would respond by dropping the link on the fiber optic
port. In this way, the AT-PB1005G 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 fiber optic cabling, the unit
would drop the link to the twisted pair port.
The value to this type of network monitoring and fault notification is that
some hubs and switches can be configured to take a specific action in
the event of the loss of connection on a port. In some cases, the unit can
be configured to seek a redundant path to a disconnected end-node or
send out a trap to a network management station, alerting the network
administrator of the problem.
Note
MissingLink or Smart MissingLink is disabled when you perform a
link test. Consequently, to ensure that the MissingLink or Smart
MissingLink is enabled on the media converter, always set the Mode
Selection button so that the ML or SML LED is green during normal
network operations.