This table contains physical-layer statistics for STU-R class
devices supported by the system.
-- Note to implementor:
-- If the implementation does not support remote management
-- of STU-R class devices, then the agent must respond with
-- the appropriate error indicating that the instance does not
-- exist; that is, 'noSuchName' in response to a SNMPv1 get
-- request, and 'noSuchInstance' in response to a SNMPv2 get
-- request.