EXFO VDSL2 - Manual (Page 65)

IPTV Analysis
VDSL2, ADSL2+, and IP Triple-Play Test Set 59
Reading Results
DSL Parameters
The DSL Params tab allows you to view the pass/fail status of the
DownStream and UpStream parameters configured in the test setup.
The available test results are the
following:
³
SNR Margin is a value ranging
from 0 through 63.5 for the
minimum signal-to-noise ratio
margin.
³
Attenuation is a value ranging
from 0 through 63.5 for the
maximum attenuation.
³
Output Power is the current transmit power level that is a measure of
the absolute transmit power.
³
INP is the level of impulse noise protection.
³
Interl.Depth is interleave depth which defines the number of bits (or
bytes) in each block of data.
³
Interl.Delay is interleave delay which defines the mapping (relative
spacing) between subsequent input bytes at the interleave input and
their placement in the bit stream at the interleave output.
³
Trellis or Trellis Coded Modulation (TCM) is a type of convolutional
code which utilizes parity bits on each symbol within a continuous
data stream. When the line is connected, Trellis displays either ON or
OFF.
³
BITSwap specifies the status of the bit swapping mechanism - Active,
Not Active or Unknown - swapping bits from tone m to tone n to
prevent modem retraining.