Updated 11/12
Sunset xDSL test capture screen (hehe, my line too)

What does it mean?

FAST: Displays the Fast Path bit rate. This is the actual bit rate between the ATU-R and the ATU-C (when Fast is used)

INTER: Displays the Interleaved bit rate. This is the actual bit rate between the ATU-R and ATU-C (when the interleaved path is used). Interleaving adds some additional flow control and error correction at the expense of latency.

MAX: Displays the maximum attainable bit rate that the circuit will support

MARGN: Indicates the realized Noise Margin. This is the margin above the signal to noise ratio required to support the bit rate

ATTEN: Total attenuation, this is the measure difference in dB between the power transmitted at the near end and received at the far end.

POWER: Indicates the aggregate power level. This specifies the maximum aggregate power level allowed at the transmitter. For the downstream, the ATU-C has a maximum power level of 20dBm. For the upstream, the ATU-R has a maximum level of 13 dBm. The maximum levels are specified at the DSLAM. The modems will use the appropriate power level to achieve the bit rate over a given distance. A longer distance will require a higher output power than a shorter distance for the same bit rate

CAP: Indicated the Capacity. This measurement is an indication of line capability. It is a ratio of (achieved line rate / attainable line rate) X 100. For example, a CAP reading of 85% means the modem has the capacity to transmit 15% more line rate if required.

 

Here is a capture of a standard DSL line output on a Sunrise Telecom Sunset xDSL meter

And here is a picture of the unit as a whole: