ZyXEL Communications AMG1302-T series User Manual page 237

Table 93 Maintenance > Diagnostic > DSL Line (continued)
LABEL
DSL Line Status
Reset ADSL Line
AMG1302/AMG1202-TSeries User's Guide
DESCRIPTION
Click this to view statistics about the DSL connections.
noise margin downstream is the signal to noise ratio for the downstream part of the
connection (coming into the AMG1302/AMG1202-TSeries from the ISP). It is measured in
decibels. The higher the number the more signal and less noise there is.
output power upstream is the amount of power (in decibels) that the AMG1302/
AMG1202-TSeries is using to transmit to the ISP.
attenuation downstream is the reduction in amplitude (in decibels) of the DSL signal
coming into the AMG1302/AMG1202-TSeries from the ISP.
Discrete Multi-Tone (DMT) modulation divides up a line's bandwidth into sub-carriers
(sub-channels) of 4.3125 KHz each called tones. The rest of the display is the line's bit
allocation. This is displayed as the number (in hexadecimal format) 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 certain ADSL transmission rates, and
possibly to determine whether particular 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. There will be
some tones without any bits as there has to be space between the upstream and
downstream channels.
Click this to reinitialize the ADSL line. The large text box above then displays the progress
and results of this operation, for example:
"Start to reset ADSL
Loading ADSL modem F/W...
Reset ADSL Line Successfully!"
Chapter 26 Diagnostic
237