This attribute indicates the total number of Path Severely Errored
Seconds (PSESs) that have been counted. A PSES is declared for
second intervals containing more than x PCVs or one or more LOP
or path AIS defects. The value of x is 2400 for a 155 Mbits/sec
interface. Counting of PSES is inhibited when PUAS is counted
over the monitored second.