The DPP-IP interface's current receive side capacity in
slots per DTM frame that is actually transported. When
Dynamic Trunk functionality is disabled this is equal to
dppipRxSlots. When Dynamic Trunk functionality is enabled
this is less or equal to dppipRxSlots, since slots that are
not used by any channel need not be transported.
Requires Dynamic Trunk function support equal to 1.1 or
higher.