Cabletron Systems 2.2 Manuel D’Utilisation
Bridging
2-30
Bridge Statistics
Abort Sequences
The Abort Sequences Þeld displays the number of abort sequences transmitted by
the selected port. These occur when an adapter has frames to transmit and
receives a token, but does not detect an ending delimiter on the token after its
access control Þeld. This indicates that the token is corrupted. The station
transmits abort delimiters to halt frame transmission before its expected
end-frame sequence, re-queues the frame(s) for transmission, but does not release
the corrupt token.
the selected port. These occur when an adapter has frames to transmit and
receives a token, but does not detect an ending delimiter on the token after its
access control Þeld. This indicates that the token is corrupted. The station
transmits abort delimiters to halt frame transmission before its expected
end-frame sequence, re-queues the frame(s) for transmission, but does not release
the corrupt token.
Internal Errors
The Internal Errors Þeld displays the number of recoverable internal errors
detected by the selected port. These are recorded when a station recognizes a
recoverable internal error in its adapter, and removes itself from the ring. This is
considered a solid hard error, since the ring automatically reconÞgures.
detected by the selected port. These are recorded when a station recognizes a
recoverable internal error in its adapter, and removes itself from the ring. This is
considered a solid hard error, since the ring automatically reconÞgures.
Lost Frames
The Lost Frames Þeld displays the number of non-returned frames detected by
the selected port. These occur when a transmitting stationÕs TRR (Timer, Return to
Repeat) timer expires (after 4.1 milliseconds) before the end of its frame returns.
This timer ensures that the station returns to the data repeat state (i.e., retrieves
the token, strips it of data, and issues a new token to the ring). Lost frames are
usually caused by a station entering or leaving the ring as the frame is circulating.
the selected port. These occur when a transmitting stationÕs TRR (Timer, Return to
Repeat) timer expires (after 4.1 milliseconds) before the end of its frame returns.
This timer ensures that the station returns to the data repeat state (i.e., retrieves
the token, strips it of data, and issues a new token to the ring). Lost frames are
usually caused by a station entering or leaving the ring as the frame is circulating.
Congestion Errors
The Congestion Errors Þeld displays the number of times the selected port has not
been able to copy a protocol data unit (PDU) addressed to it because of a lack of
internal buffering.
been able to copy a protocol data unit (PDU) addressed to it because of a lack of
internal buffering.
F. C. Errors
The F. C. Errors Þeld displays the number of protocol data units (PDUs)
addressed to the selected station with the A bits already set to 1. This error
indicates that a possible electrical line disturbance or a duplicate address has
occurred on the ring.
addressed to the selected station with the A bits already set to 1. This error
indicates that a possible electrical line disturbance or a duplicate address has
occurred on the ring.
Token Errors
The Token Errors Þeld displays the number of times that the selected station,
acting as the active monitor, detected an error condition that needed a token
transmitted.
acting as the active monitor, detected an error condition that needed a token
transmitted.
Soft Errors
The Soft Errors Þeld displays the number of soft errors detected by the selected
port. Although soft errors do not cause ring failure, they degrade the performance
of the ring network.
port. Although soft errors do not cause ring failure, they degrade the performance
of the ring network.
Hard Errors
The Hard Errors Þeld displays the number of immediately recoverable fatal errors
detected by the selected port. These are errors which halt normal operation of the
ring, and are usually caused by faults in the ring hardware, equipment, or wiring.
detected by the selected port. These are errors which halt normal operation of the
ring, and are usually caused by faults in the ring hardware, equipment, or wiring.