This counts seconds during which the TDM path carried over this pseudowire was considered available. Comparing ASP against TTP for this PW gives the actual path-layer availability percentage for the service, the figure that belongs in an SLA report for the emulated circuit rather than the service-layer UAS/AS pair alone -- and this specific object covers the current, still-open 24-hour interval -- the earliest daily-scale warning available before the full day's history bin closes. For example, so far in the current, still-running 24-hour interval, this pseudowire might show this counter at 43250 -- a concrete count the admin can trend against neighboring bins to judge whether the condition it reflects is worsening.