@renluop: QLN and HLog are quite different things. The only connection is that both are measured immediately before sync.
QLN (Quiet Line Noise) is a measure of the background noise on the line over the frequency range in the absence of any DSL activity.
HLog (Logarithmic Channel Characteristics Function) is effectively the gain of the line over the frequency range, in logarithmic units (dB). This is the inverse of attenuation.
The 2 graphs are probably combined with other info to give your tone graph...
No, that's not the case. All the other reported values are determined in real time.