The value of tmnxOamPingCtlMtuEndSize specifies the size of the last
OAM Echo message sent as part of an 'mtuPing' test.
Setting this object to a non-zero value is a prerequisite for starting
an 'mtuPing' test. Its value must be greater than or equal to
the value of tmnxOamPingCtlMtuStartSize.
An attempt to set this object from a non-zero value to zero will fail
with a wrongValue error.