Controls creation/deletion of entries in this table according to the
RowStatus textual convention, constrained to support the following
values only:
createAndGo
destroy
To create an entry in this table, the following entry objects MUST be
explicitly configured:
usdSmdsSubIfRowStatus
usdSmdsSubIfLowerIfIndex
In addition, when creating an entry the following conditions must hold:
A value for usdSmdsSubIfIndex must have been determined previously,
by reading usdSmdsSubNextIfIndex.
The interface identified by usdSmdsSubIfLowerIfIndex must exist.
A corresponding entry in ifTable/ifXTable/usdIfTable is created/destroyed
as a result of creating/destroying an entry in this table.