A read-only Counter32 giving the total number of Available Seconds accumulated since the link was last administratively brought up, computed as Error Free Seconds plus Errored Seconds minus Severely Errored Seconds. This is essentially the link's cumulative usable-time metric, distinct from raw uptime, since it explicitly excludes the seconds too severely impaired to be considered available for service. For example, an SLA calculation comparing p2mpSuAvailableSeconds against total elapsed time since Link Admin Up would give a defensible availability percentage that discounts severely errored periods.