This Counter64 gives the current total number of send-direction packets lost for this Dynamic VPath, as detected by the appliance's own loss tracking rather than simple drop counting. An admin uses it as a more precise loss indicator when assessing quality of a site-to-site tunnel for latency-sensitive traffic like voice or video. For example, a rising lost-packet count on a VPath carrying VoIP would explain reports of choppy audio on calls to that site.