Information on one Discovery Domain Set (DDS) registered
in the iSNS Server instance. The cIsnsNextIdxDds managed
object is used to determine an available cIsnsDdsId that
should be used for row creation. During creation of a
row, if a symbolic name is not provided in
cIsnsDdsSymbolicName, then a unique symbolic name will be
provided by the iSNS Server. If a DDS is deleted, then
each entry associating the DDS with a DD in the table
cIsnsDdsMemberTable is removed. The creation and deletion
of DDS's should be carefully handled so as to not disrupt
a DDS created by a storage entity through the iSNS
protocol directly.