EXFO FTB/IQS-85100G Packet Blazer for FTB-500/IQS-600 - Manual (Page 228)

Test Results
218 FTB/IQS-85100G
Performance Monitoring
Near-End

EFS (Error Free Second) (G.821, G.828, and G.829): Gives the number
of seconds within which no error occurred.

EC (Error Count) (G.821 only): Gives the number of bit errors.

EB (Errored Block) (G.828, and G.829): Gives the count of blocks in
which one or more bits are in error.

ES (Errored Second)
For G.821, and M.2100 OOSM: Gives the number of seconds within
which one or more bit error occurred, or during which Loss Of Signal
(LOS) or AIS is detected.
For G.828, G.829, and M.2101: Gives the number of seconds within
which one or more anomalies (EB, etc.) occurred, or at least one
defect occurred.

SES (Severely Errored Second)
For G.821, and M.2100 OOSM: Gives the number of seconds within
which a bit error ratio is  10
-3
, or during which one defect (LOS/AIS) is
detected.
For G.828, G.829 and M.2101: Gives the number of seconds within
which anomalies (EB, etc.) are  30%or at least one defect occurred.

BBE (Background Block Error) (G.826, G.828, G.829, and M.2101):
Gives the count of Errored Block not occurring as part of a SES.