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Hub Reference
Auto-Partitioning
The hub will automatically partition (temporarily disable) one of its ports if
a collision condition exists for an excessive duration (between 1024 and
2048 bit times) or occurs during each of 32 consecutive attempts to transmit.
The hub monitors the partitioned port and automatically re-enables the port
when a minimum length packet can be successfully transmitted or received
without a collision occurring.
Excessive collisions may be caused by faulty wiring. If a port's transmit
(Tx +/-) wires have been shorted to the receive (Rx +/-) wires of any port, a
collision will be detected when that port attempts to transmit. If a port's
receive (Rx +/-) wires are not connected properly, collisions may occur
because the hub cannot detect the presence of network traffic on that port
and may thus transmit at inappropriate times.
A port may occasionally also become partitioned when network traffic is
extremely heavy causing an abnormally high collision rate.
Link Beat
Type 10Base-T devices use a signal called link beat (also called link test
pulse). This signal informs the hub of the presence of a device connected to
it over twisted-pair cable and of the integrity of the twisted-pair link between
them. The hub will not transmit packets out of twisted-pair ports that do not
sense the link beat signal.
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Table of Contents
Troubleshooting
