ccdTdrIfResultPairLengthUnit 1.3.6.1.4.1.9.9.390.1.2.2.1.7

The measurement unit on the length or the distance to fault point for the cable pair. 'unknown' -- none of the following. 'meter' -- the unit is meter. 'centimeter' -- the unit is centimeter. 'kilometer' -- the unit is kilometer.