Smart Auto-Sensing - 3Com 3C17300-US Implementation Manual

Smart Auto-sensing

Smart auto-sensing allows auto-negotiating multi-speed ports, such as
10/100 Mbps or 10/100/1000 Mbps, to monitor and detect a high error
rate on a link, or a problem in the "physical" interconnection to another
port and react accordingly. In other words, auto-negotiation may "agree"
upon a configuration that the cable cannot sustain; smart auto-sensing
can detect this and adjust the link accordingly.
For example, smart auto-sensing can detect network problems, such as
an unacceptably high error rate or a poor quality cable. If both ends of
the link support 100/1000 Mbps auto-negotiation, then auto-sensing
tunes the link to 100 Mbps to provide an error-free 100 Mbps connection
to the network.
An SNMP Trap is sent every time a port is down-rated to a lower speed.
Conditions that affect smart auto-sensing:
Smart auto-sensing will not operate on links that do not support
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auto-negotiation, or on links where one end is at a fixed speed. The
link will reset to the higher speed of operation when the link is lost or
the unit is power cycled.
Smart auto-sensing can only be configured for the whole Switch and
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not on a per port basis.
GBIC or SFP ports do not support smart auto-sensing.
Port Features 25