Cabletron Systems LR-2000 User Manual - page 16
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TESTING AND TROUBLESHOOTING
Figure 4-2. LANVIEW LEDs
Jam (JAM) LED
This red LED normally flashes on and off to indicate that the LR-2000 is propagating a
collision from the segment on which the collision is occurring to the other segment
connected to the repeater. When this LED flashes, a pattern of 1,0 is sent to each segment
to indicate that a collision is occurring on one of the segments. What will be observed is
that the COLLISION LED for one segment will flash, indicating a collision, causing the
JAM LED to flash.
NOTE: There is one Receive, Collision, and Fault LED for each port on the LR-2000.
Receive (RECEIVE) LED
This yellow LED normally flashes on and off to indicate that the LR-2000 is repeating the
data packet being received from that segment. The rate at which the LED flashes will
increase as network activity increases.
Collision (COLLISION) LED
This red LED normally flashes on and off to indicate that a collision is occurring on the
indicated segment. The rate at which the LED flashes will increase as network activity
increases, since more collisions are likely occur.
Fault (FAULT) LED
A lit red FAULT LED indicates that the LR-2000 has disconnected that segment from the
network because 32 consecutive collisions have occurred on the segment, or because the
collision detector was on for longer than 2.4 ms. The FAULT LED will go out after one
packet is transmitted onto the segment with the fault without causing a collision.