EXFO FTB-8510B Guia Del Usuario página 1159

Common Tabs
Performance Monitoring (PM)
DM (Degraded Minutes) (G.821 only): A Degraded Minute is the
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number of minutes in which the estimated error rate exceeds 10 but
-3
does not exceed 10 . DM is determined by collecting all of the
Available Seconds, removing any SES grouping the result in 60-second
long groups and counting a 60-second long group as degraded if the
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cumulative errors during the seconds present in the group exceed 10 .
SEP (Severely Errored Period) (G.828 only): A sequence between 3 to
9 consecutive SES. The sequence is terminated by a second which is
not a SES.
SEPI (Severely Errored Period Intensity) (G.828 only): Gives the count
of SEP events in available time, divided by the total available time in
seconds.
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SONET/SDH Application