User guide

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Compaq Netelligent 1009B 10Base-T Hub User Guide
Writer:
Chris Seiter
Project:
Hardware Description
Comments:
File Name:
1009B_2.DOC
Last Saved On:
8/21/97 1:01 PM
Collision
Label (%) Color Function
1% 3% 5% Green
10% 15+% Amber (yellow)
Indicates the percentage of packet collisions
occurring out of the total packets received by
the hub.
Collisions occur when two or more devices connected to a hub attempt to
transmit data simultaneously on the network. When a collision occurs, devices
pause and then re-transmit after a random wait period. Because wait periods
differ among devices, successive collisions become increasingly improbable.
The Collision LEDs help you monitor the percentage of packet collisions that
occur relative to the total packets received by the hub. Similar to Utilization
LEDs, the Collision LEDs have five numbers that represent collision
percentage. When collisions reach a level marked on the LED display, the
corresponding LED lights.
For example, if packet collisions reach 1%, the LED labeled 1% lights.
However, if collisions go beyond 1% (for example, 15%), the LED labeled 15+
and all the other LEDs before it (that is, 1, 3, 5, and 10) also light in rapid
succession.
NOTE: After 32 consecutive collisions occur on the cable segment connected to a
port, that port is automatically partitioned by the hub. The hub automatically
reconnects this port when a data packet longer than 512 bits (normal) is transmitted
by the partitioned port without collision.