Cabletron Systems SPECTRUM TRMMIM, User Manual

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Ring Map
3-16 Viewing Ring-level Information
Basic performance information is provided regardless of which error type has
been selected for display:
Frames The number of frames transmitted by the associated
station as measured using the currently selected
calculation mode.
Bytes The number of bytes transmitted by the associated
station as measured using the currently selected
calculation mode.
The remainder of the window displays the counts for the error type or types you
selected when you launched the window. Remember, these counts reflect which
stations are reporting the error to the Ring Error Monitor, not which stations are
experiencing the error condition.
Total Errors
The number of soft errors detected by the associated station as measured using
the currently selected calculation mode.
Isolating Errors
Line Errors The count of line errors detected by the associated station
during the last statistics poll interval. A line error
indicates the presence of a coding violation between the
starting and ending delimiters of data, a frame check
sequence error, or a code violation in a token. These can
be caused by power surges on the ring; they are counted,
but initiate no other recovery procedures.
Burst Errors The count of burst errors detected by the associated
station. A burst error occurs when five half-bits of
Manchester-encoded data are received by a station
without a phase change (a signal transition from 0 to 1 or
from 1 to 0). This error is normal when stations enter or
leave the ring without phantom current; however, it can
also indicate a problem with the receiver on the reporting
node, the transmitter on its NAUN, or the cabling or hub
hardware between them. Burst errors will cause the
active monitor to initiate the ring purge process, and may
cause frames to be lost on the ring.
TIP
If the error is an isolating error, you can narrow the fault to a certain domain – that is
the adapter card of the reporting station or its downstream neighbor – or to the cabling
between the two stations. Non-isolating errors cannot be narrowed to a fault domain
(with the exception of Congestion errors), because they could be caused by any station on
the ring.