ZyXEL Communications AAM1212-51, User Manual

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AAM1212-51/53 Series User’s Guide
372 Chapter 52 ADSL Commands
52.2.10 SELT Diagnostic Set Command
Syntax:
ras> adsl linediag setselt <port number>
This command has the AAM1212 perform a single end line test on the specified port. This test
checks the distance to the subscriber’s location.
Note: The port must have an open loop. There cannot be a DSL device, phone, fax
machine or other device connected to the subscriber’s end of the telephone
line.
The test takes at least 15 seconds. You can run the SELT Diagnostic Get Command to check
the status of the test and to look at the results.
snrm:
This is the upstream and downstream Signal-to-Noise Ratio Margin (in dB). A
DMT sub-carrier’s SNR is the ratio between the received signal power and the
received noise power. The signal-to-noise ratio margin is the maximum that the
received noise power could increase with the AAM1212 still being able to meet
its transmission targets.
attndr:
This is the upstream and downstream Attainable Net Data Rate (in bit/s).
farEndActatp:
This is the upstream and downstream Far End Actual Aggregate Transmit
Power (in dBm)
i
This is the index number of the DMT sub-carrier.
li.rl
The channel characteristics function is represented in linear format by a scale
factor and a complex number. This is the real part of the complex number used
in producing the channel characteristics function for this sub-carrier.
li.im
The channel characteristics function is represented in linear format by a scale
factor and a complex number. This is the imaginary part of the complex number
used in producing the channel characteristics function for this sub-carrier
log
This is a format for providing channel characteristics. It provides magnitude
values in a logarithmic scale. It is measured in dB. This can be used in analyzing
the physical condition of the DSL line.
QLN
The Quiet Line Noise for a DMT sub-carrier is the rms (root mean square) level
of the noise present on the line, when no DSL signals are present. It is measured
in dBm. The QLN can be used in analyzing crosstalk.
SNR
This is the upstream and downstream Signal-to-Noise Ratio (in dB). A DMT sub-
carrier’s SNR is the ratio between the received signal power and the received
noise power. The SNR can be used in analyzing time dependent changes in
crosstalk levels and line attenuation (such as those caused by temperature
variations and moisture).
Table 97 Line Diagnostics Get 992.3 Command (continued)
LABEL DESCRIPTION