A count of the number of Loopback Control OAMPDUs transmitted
on this interface.
An Loopback Conrol OAMPDU is indicated by a valid frame with
(1) destination MAC address equal to that of the reserved MAC
address for Slow Protocols (See 43B of [802.3ah]), (2) a
lengthOrType field equal to the reserved type for Slow
Protocols, (3) a Slow Protocols subtype equal to that of the
subtype reserved for OAM, and (4) an OAMPDU code equals the
OAM Loopback Control code.
Discontinuities of this counter can occur at re-initialization
of the management system, and at other times as indicated by
the value of the ifCounterDiscontinuityTime.