This records the sysUpTime value at the most recent moment any of this pseudowire's Counter32 or Counter64 statistics suffered a discontinuity (typically a reload or counter reset), and it reads zero if no discontinuity has ever occurred since the management subsystem last initialized. Every monitoring system must check this object before trusting a sudden drop in cpwVcPerfTotalInHCPackets or similar totals, since a legitimate discontinuity looks identical to an actual traffic outage unless you cross-check this timestamp. If this value matches the router's own last-reload time, the counter reset was caused by the box rebooting, not a signaling failure on the VC itself.