An integer used only for indexing purposes.
Generally monotonically increasing from 1 as new
applications are installed.
The value for each installed application must
remain constant at least from one re-initialization of
the network management entity which implements this
MIB module to the next re-initialization.
The specific value is meaningful only within a given SNMP
entity. A sysApplInstallPkgIndex value must not be re-used
until the next agent entity restart in the event the
installed application entry is deleted.