EXFO FTB-800 Series for FTB-1 - Manual (Page 280)

Test Results
270 FTB-700G/800 Series
Alarms/Errors
OTUx
Note: Available for OTU2, OTU2f, OTU1f, OTU2e, OTU1e, and OTU1.
Alarms

AIS (Alarm Indication Signal)
RX: Polynomial number 11 (PN-11) is over all OTU frame bits including
FAS and MFAS for at least 3 consecutive 8192 bit-interval.
TX: Generates polynomial number 11 (PN-11) over all OTU frame bits
including FAS and MFAS continuously.

BDI (Backward Defect Indication)
RX: The BDI bit in the SM overhead field (byte 3, bit 5) is “1” for at least
5 consecutive OTU frames.
TX: Generates “1” for the BDI bit in the SM overhead field (byte 3, bit 5)
continuously.

BIAE (Backward Incoming Alignment Error)
RX: The BEI/BIAE bits in the SM overhead field (byte 3, bits 1 to 4) are
“1011” for at least 3 consecutive frames.
TX: Generates “1011” for the BEI/BIAE bits in the SM overhead field
(byte 3, bits 1 to 4) continuously.

IAE (Incoming Alignment Error)
RX: The IAE bit in the SM overhead field (byte 3, bit 6) is “1” for at least
5 consecutive OTU frames.
TX: Generates “1” for the IAE bit in the SM overhead field (byte 3, bit 6)
continuously.