Chapter 26 Diagnostic

Table 97 Maintenance > Diagnostic > DSL Line (continued)

LABEL

DESCRIPTION

DSL Line Status

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 AMG1312-T Series 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 AMG1312-T

 

Series is using to transmit to the ISP.

 

attenuation downstream is the reduction in amplitude (in decibels) of the DSL signal

 

coming into the AMG1312-T Series 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.

 

 

Reset ADSL Line

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!"

 

223

AMG1312-T Series User’s Guide