Indicates mandatory state of the VTU-O line. This is a bit-map of possible conditions. The various bit positions are:

0 noDefect There no defects on the line

1 lossOfFraming VTU-O failure due to not receiving valid frame.

2 lossOfSignal VTU-O failure due to not receiving signal.

3 lossOfPower VTU-O failure due to loss of power. Note: the Agent may still function.

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-O failure due to inability to link with VTU-R.

6 dataInitFailure VTU-O failure during initialization due to bit errors corrupting startup exchange data.

7 configInitFailure VTU-O failure during initialization due to peer VTU not able to support requested configuration

8 protocolInitFailure VTU-O failure during initialization due to incompatible protocol used by the peer VTU.

9 noPeerVtuPresent VTU-O failure during initialization due to no activation sequence detected from peer VTU.

This is intended to supplement ifOperStatus.