Cabletron Systems MMAC-Plus SFCS-1000, Руководство по настройке

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4-7
SONET Configuration
4.6 SONET Error Counter Descriptions
sonetSectionBIPs The number of Section BIP-8 (Bit Interleaved
Parity) errors that have been detected since the
last time the port has been reset. The calculated
BIP-8 code is compared with the BIP-8 code
extracted from the B1 byte of the following
frame. Differences indicate that a section level bit
error has occurred.
sonetSectionLOSs The number of seconds in which Loss Of Signal
(LOS) has occurred. A LOS is declared when a
pattern of all zeros is detected for 20 +/- 3ms.
LOS is cleared when two valid framing words
are detected and during the intervening time no
LOS condition is detected.
sonetSectionLOFs The number of seconds in which Loss Of Frame
(LOF) has occurred. A LOF is declared when an
out-of-frame (OOF) condition persists for 3ms.
The LOF is cleared when an in-frame condition
persists for 3ms. While in-frame, the framing
bytes (A1, A2) in each frame are compared
against the expected pattern. Out of frame is
declared when four consecutive frames contain-
ing one or more framing pattern errors have
been received.
sonetLineBIPs The number of Line BIP-24 (Bit Interleaved Par-
ity) errors that have been detected since the last
time the port has been reset. The calculated
BIP-24 code is based on the line overhead and
synchronous payload envelope (SPE) of the
STS-3c stream. The line BIP-24 code is a bit inter-
leaved parity calculation using even parity. The
calculated code is compared with the BIP-24
code extracted from the B2 bytes of the following
frame. Differences indicate that a line layer bit
error has occurred.
sonetLineFEBEs The number of line Far End Block Errors (FEBE)
that have been detected since the last time the
port has been reset.