This counter tracks the number of SSCOP (QSaal) receive discards on this port, i.e. inbound PDUs at the SSCOP layer that were dropped rather than delivered up to signaling, per the description. Because a discarded receive PDU can silently swallow a Q.93b message like SETUP or RELEASE before Q.93b even sees it, this counter is a useful early check when calls seem to vanish without any corresponding svcAtmFailedCall entry or cause code being recorded. A steadily nonzero value here on an otherwise healthy-looking port suggests receive buffer pressure specific to this VC.