The value of tmnxDot1agCfmGracePeriod indicates whether or not the
node is locally executing a grace period. A value of 'true' indicates
that all peer timeouts are extended locally and eligible MEPs are
transmitting grace period information. A value of 'false' indicates
no grace period information is transmitted and standard values are
used for timing out remote peers.
Note that for a local MEP to be eligible for grace period transmission
it must be admin up and ccm-enabled. Additionally, for any
transmission to occur tmnxDot1agCfmGraceTxEnable must be set to
'true'.