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