ZyXEL Communications ALC1224, Руководство пользователя

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ALC1224 User’s Guide
ADSL Port Commands 11-3
<slot-port> = The number of the slot where the ALC1224 is located and the number of
an ADSL port.
This command forcibly enables the specified ADSL port.
The factory default of all ports is disabled. A port must be enabled before data transmission can
occur. An enabled but disconnected ADSL port generates more heat than an operating port. To
minimize heat generation and to enhance reliability, remember to disable a port when it is not in
use.
11.3.4 Linedata Command
Syntax:
lcman command <slot> linedata <port>
where
<slot>
=
The number of the slot where the ALC1224 is located.
<port>
=
A port number (1 ~ 24).
This command shows the line bit allocation of an ADSL port.
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.
“DS carrier load” displays the number of bits received per DMT tone for the downstream channel (from the
ALC1224 to the subscriber’s DSL modem or router).
“US 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 ALC1224).
The bit allocation contents are only valid when the link is up.
In the following example, the downstream channel is carried on tones 65 to 241 and the upstream channel is carried
on tones 7 to 29 (space is left between the channels to avoid interference).