cAdslAtucDmtConfBitSwapFrom

CISCO-ADSL-DMT-LINE-MIB · .1.3.6.1.4.1.9.9.130.1.14.1.8

Object

column r/w dB Integer32
Bitswapping attempts to maintain an acceptable margin for
each bin; equalizing the margin across all bins through bit
reallocation, thereby maximizing error performance.
              
The ATU-C performs bitswapping by monitoring the margin
measured for each bin by the transmitter.  If a bin's margin
falls below adslAtucConfTargetSnrMgn and the difference
between the margin and adslAtucConfTargetSnrMgn exceeds
the value of this object, then the ATU-C marks a bin as
a 'from' bin.
              
The ATU-C attempts to equalize the margin across the bins by
swapping bits out of bins marked 'from' into bins marked 'to'.
When the ATU-C swaps a bit out of bin, it decreases its b(i).
Thus, the bins constellation is smaller. which increases its
margin.  When the ATU-C swaps a bit into a bin, it increases
its b(i).  Thus, the bins constellation is larger, which
decreases its margin.
              
If this value is too small, then the ATU-C may frequently
toggle the bit allocation on bins, and if impulse noise is
present, this can cause errors.  If this value is too large,
then the ATU-C may not identify an adequate number of bins
that it can swap bits 'from', thereby decreasing the chances
for the ATU-C to equalize the margin across all the bins.
Unequalized margin across all the bins translates into poor
error performance.

Context

MIB
CISCO-ADSL-DMT-LINE-MIB
OID
.1.3.6.1.4.1.9.9.130.1.14.1.8
Type
column
Access
readwrite
Status
current
Units
dB
Parent
cAdslDmtLineConfProfileEntry
Table
cAdslDmtLineConfProfileTable
Siblings
13

Syntax

dB Integer32

Values & Constraints

Object Constraints
range: 1-9

Related Objects

Sibling Objects