EXFO IQS-8100 Series Transport Blazer for IQS-600 - Manual (Page 523)

Common Tabs
SONET/SDH Application 509
Performance Monitoring (PM)
³
DM (Degraded Minutes) (G.821 only): A Degraded Minute is the
number of minutes in which the estimated error rate exceeds 10
-6
but
does not exceed 10
-3
. 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
cumulative errors during the seconds present in the group exceed 10
-6
.
³
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.
³
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.