The stratum at which the device exists in the Synchronous
Digital Hierarchy (See American National Standards
Institute, ANSI T1.101, 'Synchronization Interface for
Digital Networks' and Bell Communications Research,
GR-436-CORE, 'Digital Network Synchronization Plan' for
more detailed information regarding stratum.).
The resident NCDP entity uses the value of this object to
enforce the network clock distribution stratum hierarchy.
This object is only used by the NCDP protocol entity.