The number of packets seen from the destination host to the
source host during this sampling interval, counted
using the rules for counting the nlMatrixSDPkts object. (Note
that the corresponding nlMatrixSDPkts object selected is the
one whose source address is equal to nlMatrixTopNDestAddress
and whose destination address is equal to
nlMatrixTopNSourceAddress.)
Note that if the value of nlMatrixTopNControlRateBase is equal
to nlMatrixTopNPkts, the sort of topN entries is based
entirely on nlMatrixTopNPktRate, and not on the value of this
object.