User's Manual

228
MSAP2000 AAMS User’s Guide
Discrete Multi-Tone (DMT) modulation divides up a line’s bandwidth into tones.
This command displays the number of bits transmitted for each tone. This can be
used to determine the quality of the connection, whether a given sub-carrier loop
has sufficient margins to support ADSL transmission rates, and possibly to
determine whether certain specific types of interference or line attenuation exist.
Refer to the ITU-T G.992.1 recommendation for more information on DMT.
The better (or shorter) the line, the higher the number of bits transmitted for a
DMT tone. The maximum number of bits that can be transmitted per DMT tone is
15.
“upstream carrier load” displays the number of bits transmitted per DMT tone for
the upstream channel (from the subscriber’s DSL modem or router to the
MSAP2000 AAMS).
“downstream carrier load” displays the number of bits received per DMT
tone for the downstream channel (from the MSAP2000 AAMS to the
subscriber’s DSL modem or router).
The bit allocation contents are only valid when the link is up.
In the following example, the upstream channel is carried on tones 7 to 39 and the
downstream channel is carried on tones 53 to 259 (space is left between the
channels to avoid interference).
Figure 143 Linedata Command Example
ras> statistics adsl linedata 1
[port 1]
up stream carrier load: number of bits per symbol(tone):
tone 0- 19: 00 00 00 00 00 00 02 03 04 05 - 06 07 07 07 07 07 07 07 08 08
tone 20- 39: 08 08 07 08 08 07 07 06 06 05 - 04 03
down stream carrier load: number of bits per symbol(tone):
tone 0- 19: 00 00 00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 00 00 tone 20- 39: 00 00
00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00 00 00 tone 40- 59: 00 00 00 00 00 00 00 00 00
00 - 00 00 00 01 01 01 01 01 01 02 tone 60- 79: 02 02 02 02 00 02 02 02 02 02 - 02 02 02 02 02 02
02 02 02 02 tone 80- 99: 02 02 02 02 02 02 02 02 02 02 - 02 02 02 02 02 02 02 02 02 02 tone
100- 119: 02 02 02 02 02 02 02 02 02 02 - 02 02 02 02 02 02 02 02 02 02 tone 120- 139: 02 02 02 02
02 02 02 02 02 02 - 02 02 02 02 02 02 02 02 02 02 tone 140- 159: 02 02 02 02 02 02 02 02 02 02 -
02 02 02 02 02 02 02 02 02 02 tone 160- 179: 02 02 02 02 02 02 02 02 02 02 - 02 02 02 02 02 02 02
02 02 02 tone 180- 199: 02 02 02 02 02 02 02 02 02 02 - 02 02 02 02 02 02 02 02 02 02 tone 200-
219: 02 02 02 02 02 02 02 02 02 02 - 02 02 02 02 02 02 02 02 02 02 tone 220- 239: 02 02 02 02 02
02 02 02 02 02 - 02 02 02 02 02 02 02 02 02 02 tone 240- 259: 02 02 02 02 02 02 02 02 02 02 - 02
02 02 02 02 02
29.4.3 Statistics ADSL Lineinfo Command
Syntax:
statistics adsl lineinfo <portlist>