Allied Telesis AT-MC103ST/FSx - Manual (Page 17)

AT-MC100 Series Installation Guide
5
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 node or send out a trap to a network
management station, and so alert the network administrator of the problem.
Note
The MissingLink feature is disabled when you perform a link test with
the Link Test/MissingLink button. Consequently, to ensure that the
MissingLink feature is activated on the media converter, always set the
button to the M/L ON (IN) position during normal network operations.
However, if left in this position and there is a network failure, after
recovery you must physically set the unit to LNK TST (OUT) then back
to M/L ON (IN) for the media converter to resume passing network
traffic.
Auto-negotiation Button
The auto-negotiation button, located on the front panel, disables the auto-
negotiation feature (IEEE 802.3u) of the media converter. The media
converter uses auto-negotiation to determine the duplex mode of the ports.
The duplex mode refers to the manner in which an end-node sends and
receives data on the network. An end-node can operate in either half- or full-
duplex mode. A node operating in half-duplex can either send or receive data,
but not both at the same time. An end-node operating in full-duplex can send
and receive data simultaneously. The best network performance is achieved
when an end-node can operate in full-duplex mode.
In most configurations, you will want to leave the auto-negotiation button
activated so the unit can determine the appropriate duplex mode, based on the
capabilities of the end-nodes. For example, the auto-negotiation feature on the
media converter should be left activated in situations where both end-nodes
are also capable of auto-negotiation, or where both end-nodes have been pre-
set to the same mode or are capable of operating in only one duplex mode, such
as half-duplex.
Note
After a configuration change, you must reset the media converter by
powering OFF then powering ON the unit