Indicates current state of the Vtu 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 failure due to not receiving
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.
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.