A count of OAMPDUs passed by the OAM subordinate sublayer
to the OAM sublayer. This counter is incremented on
reception of a valid frame with (1) a destinationField
equal to the reserved multicast address for Slow_Protocols
specified in CROSS REF Table 43B-1, (2) lengthOrType field
value equal to the reserved Type for Slow_Protocols as
specified in CROSS REF Table 43B-2, (3) a Slow_Protocols
subtype value equal to the subtype reserved for OAM as
specified in Table 43B-3.