Spirent SmartBits System, Справочное руководство

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Chapter 11: ATM Cards
ATM Alarms
152 SmartBits System Reference
Path Alarms:
•
AIS . Path Alarm Indication Signal is set whenever the pointer values in bytes H1 and
H2 are all ones in 3 consecutive frames. Path AIS is cleared whenever a bit pattern
other than all ones is read for bytes H1 and H2.
•
FERF . The path Far End Receive Failure, also called the Remote Defect Indicator, is
set when a binary 110 pattern is detected in bits 6, 7, and 8 of the K2 byte for five
consecutive frames. Line AIS is cleared when a pattern other than 110 is detected in
the K2 byte for five consecutive frames.
•
Yellow . Path Yellow alarm is set to 1 when bit 5 in the G1 byte is 1 for 5 consecutive
frames. This bit is cleared when bit 5 of the G1 byte is zero for 5 consecutive frames.
•
LOCD . Loss of cell delineation is set when seven incorrect HEC values are received.
LOCD is cleared when seven consecutive correct HEC values are received.
ATM Alarms, AT-9034B and AT-9045B SmartCards
In SmartWindow, select the Alarms tab from the Statistics window to display the
following alarm conditions for the test:
•
LOCD . For DS3 and E3 G.832 cell framing modes only. Loss of cell delineation.
This condition is declared when seven consecutive HEC errors occur.
– AT-9045B only: For Direct Cell and PLCP mapping modes.
•
OOF . Out of frame (OOF) condition detected by the DS3 or E3 framer.
– For AT-9045B DS3 framing: An out of frame condition is declared when 3 out of
4 M-frames contain M-bit or when three out of 16 F-bits are in error.
– For AT-9034B E3 G.832 cell framing: An out of frame condition is declared when
four consecutive A1/A2 framing patterns are errored. In E3 PLCP framing mode
OOF is declared when there are four consecutive FAS pattern failures.
•
FERF . Far End Receive Failure.
– For AT-9045B DS3: The FERF error (both X bits are low) in an M-frame.
– For AT-9034B E3 cell framing mode: The FERF bit in MA is high.
•
AIS . Alarm indication signal detected in the DS3 or E3 frame.
– For AT-9045B DS3: AIS is declared when 1010… payload has valid framing and
parity, equal X-bits, and all subviral 3 C-bits set to 0.
– For AT-9034B E3: AIS is declared if an unframed all ones pattern (less than
0.25% zero content) is detected.
•
Idle . For AT-9045B only: Idle code signal detected by the DS3 framer.
A DS3 idle cell is a 1100… payload with valid framing and parity, equal X-bits, and
all C-bits set to 0.