This counts events where the receive-side PDV jitter buffer filled completely, forcing the device to discard incoming packets it had no room to buffer. Overrun on this pseudowire is the opposite failure mode from Underrun -- packets arriving faster or burstier than the buffer was sized for -- and a climbing count here suggests the buffer depth should be increased or the network path is delivering unexpectedly bursty traffic -- and this specific object covers the current, still-open 15-minute interval -- a value that keeps climbing until the interval closes and rolls into history. For example, so far in the current, still-running 15-minute interval, this pseudowire might show this counter at 2 -- a concrete count the admin can trend against neighboring bins to judge whether the condition it reflects is worsening.