This counts the total number of valid packets transmitted over this specific pseudowire service instance. Comparing TxPkt on this PW against the remote end's RxPkt (where visible) is how an admin estimates one-way packet loss across the network path carrying this specific service -- 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 50000 -- a concrete count the admin can trend against neighboring bins to judge whether the condition it reflects is worsening.