The value of tmnxCpmProtEthCfmPolLevelSet specifies a set of MEG
(Maintenance Entity Group) Level values. At least one Level must be
specified (i.e. the empty set is not supported).
The rate limit specified by tmnxCpmProtEthCfmPolRateLimit applies to an
Eth-CFM PDU if:
a) tmnxCpmProtPolicyId is configured against the PDU stream containing
the PDU, and
b) the PDU's MEL (MEG Level) value is an element of
tmnxCpmProtEthCfmPolLevelSet, and
c) the PDU's Opcode value is an element of
tmnxCpmProtEthCfmPolOpCodeSet.