This object is set to 'unknown' if the transceiver
is not present or its status cannot be determined.
'inUse' indicates that the transceiver is currently
selected for use by its associated port. 'standby'
indicates the associated port is using another
tranceiver, but this tranceiver could be used if
needed. 'silent' indicates that the tranceiver is
not detecting any tones on the link. 'linkFailure'
indicates that the tranceiver was unable to train for
some reason.