EXFO FTB-800 Series for FTB-1 - Manual (Page 274)

Test Results
264 FTB-700G/800 Series
Alarms/Errors
ODUx
Note: For OPUx alarms see page 269.
Alarms

AIS (Alarm Indication Signal)
RX: The STAT information in the PM byte 3, bits 6 to 8 is “111” for at
least 3 consecutive frames.
TX: Generates an all "1"s pattern in the entire ODUk signal, excluding
the frame alignment overhead (FA OH), OTUk overhead (OTUk OH)
and ODUk FTFL.

BDI (Backward Defect indication)
RX: The BDI bit in the PM overhead field (byte 3, bit 5) is “1” for at least
5 consecutive frames.
TX: Generates a “1” in the BDI (byte 3, bit 5) of the PM overhead field
continuously.

BSD (Backward Signal Degrade)
RX: The FTFL byte 128 is “00000010”.
TX: Generates a “00000010” pattern in the FTFL Byte 128 continuously.

BSF (Backward Signal Fail)
RX: The FTFL byte 128 is “00000001”.
TX: Generates a “00000001” pattern in the FTFL Byte 128 continuously.

FSD (Forward Signal Degrade)
RX: The FTFL byte 0 is “00000010”
TX: Generates a “00000010” pattern in the FTFL Byte 0 continuously.