EXFO FTB-635 Wideband Copper and DSL Test Module - Manual (Page 331)

xDSL Test Results
Copper and xDSL Tests 323
DSL Information

Interleave Delay (ms) defines the mapping (relative spacing)
between subsequent input bytes at the interleave input and their
placement in the bit stream at the interleave output.

Interleave Depth defines the number of bits (or bytes) in each
block of data.

Act. Data Rate (Mbit/s) displays the values at which the unit and
CO are connected, as negotiated during the training phase. The
values should represent what the CO was set to, unless the DSL
link is being subjected to high levels of noise/crosstalk.

Max Data Rate (Mbit/s) displays the maximum attainable bit rates
that the circuit can handle as determined by the remote terminal
and CO during the training phase. Values can be greater than the
actual bit rate.

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.

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.