EXFO MaxTester 635 - Manual (Page 308)

Running DSL/IP Tests and Viewing Results
300 MAX-635
DSL Parameter Details

Interleave Delay defines the mapping (relative spacing) between
subsequent input bytes at the interleave input and their placement
in the bit stream at the interleave output.

INP is the level of impulse noise protection.

Interleave Depth defines the number of bits (or bytes) in each
block of data.

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.

Phy-R is Broadcom proprietary Physical Layer Retransmission
technology which is used to overcome impulse noise.
G.INP is the standards based Physical Layer Retransmission
scheme for impulse noise protection and will report Active or
Not Active. G.INP state will be shown unless system is using Phy-R.