Indicates current state of the Vtu line. This is a bit-map of possible conditions. The various bit positions are: 0 noDefect There are no defects on the line. 1 lossOfFraming Vtu failure due to not receiving a valid frame. 2 lossOfSignal Vtu failure due to not receiving signal. 3 lossOfPower Vtu failure due to loss of power. 4 lossOfSignalQuality Loss of Signal Quality is declared when the Noise Margin falls below the Minimum Noise Margin, or the bit-error-rate exceeds 10^-7. 5 lossOfLink Vtu failure due to inability to link with peer Vtu. Set whenever the transceiver is in the 'Warm Start' state. 6 dataInitFailure Vtu failure during initialization due to bit errors corrupting startup exchange data. 7 configInitFailure Vtu failure during initialization due to peer Vtu not able to support requested configuration. 8 protocolInitFailure Vtu failure during initialization due to incompatible protocol used by the peer Vtu. 9 noPeerVtuPresent Vtu failure during initialization due to no activation sequence detected from peer Vtu. This is intended to supplement ifOperStatus.