Chapter 22 Diagnostic

Table 93 Maintenance > Diagnostic > DSL Line (continued)

LABEL

DESCRIPTION

DSL Line

Click this to view statistics about the DSL connections.

Status

noise margin downstream is the signal to noise ratio for the

 

 

downstream part of the connection (coming into the ZyXEL Device 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

 

ZyXEL Device is using to transmit to the ISP.

 

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

 

the DSL signal coming into the ZyXEL Device 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

Click this to reinitialize the ADSL line. The large text box above then

Line

displays the progress and results of this operation, for example:

 

"Start to reset ADSL

 

Loading ADSL modem F/W...

 

Reset ADSL Line Successfully!"

Capture All

Click this to display information and statistics about your ZyXEL Device’s

Logs

ATM statistics, DSL connection statistics, DHCP settings, firmware

 

version, WAN and gateway IP address, VPI/VCI and LAN IP address.

 

 

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P-660HN-T1H User’s Guide