ZyXEL Communications MSC1000G Series, Руководство пользователя

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Chapter 11 Profile Screens
Management Switch Card User’s Guide
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11.7.3 VDSL2 Line Profile Setup > MIB PSD Mask
Click the Modify link next to the MIB PSD MASK field in the VDSL2 Line Profile Setup screen to
open the screen as shown next. Use this screen to adjust PSD levels for tones based on the scope
down the limit PSD mask you have configured.
Up-Shift SNR Enter the number of decibels (in 0.1 dB) for the line’s up-shift SNR margin threshold.
When the line’s signal-to-noise margin goes above this number, the system attempts to
use a higher transmission rate.
Up-Shift Time Enter the number of seconds to wait before using a higher transmission rate when the
line’s SNR margin is over the up-shift SNR margin threshold.
Down-Shift SNR Enter the number of decibels (dB) for the line’s down-shift SNR margin threshold. When
the line’s signal-to-noise margin goes below this number, the system attempts to use a
lower transmission rate.
Down-Shift Time Enter the number of seconds to wait before using a lower transmission rate when the
line’s SNR margin is less than the down-shift SNR margin threshold.
SOS Time Set the period of milliseconds over which to monitor the SOS CRC and SOS NTone for
triggering the use of the SOS emergency transmission rate. The system starts using
SOS if the SOS CRCs and SOS NTones both exceed their configured limits during the
SOS time window.
SOS CRC Set the number of CRC errors allowed to occur inside the SOS Time window.
SOS NTone Set the percentage of degraded tones allowed to occur inside the SOS Time window.
SOS Max Set the maximum number of successful SOS procedures allowed within 120 seconds
before the system triggers a full re-initialization.
ROC SNR Enter the number of decibels (dB) for the line’s Robust Overhead Channel SNR margin
threshold. If
ROC Mode is set to Enable , the system adds this extra margin to the
Target SNR Margin for the ROC tones.
ROC Min INP Specify the level of impulse noise (burst) protection to apply when using the Robust
Overhead Channel.
This is the number of consecutive DMT symbols that can be completely corrected. A
higher symbol value provides higher error correction capability, but it causes overhead
and higher delay which may impact multimedia data receiving quality.
ROC Mode Turn the use of the ROC on or off.
Dynamic Depth
Mode Enable dynamic depth mode to have the system automatically change the interleave
depth (amount of error correction) based on the line’s noise levels.
Apply Click Apply to save the changes in this screen to the system’s volatile memory. The
system loses these changes if it is turned off or loses power, so use the Config Save
link on the navigation panel and then the Save button to save your changes to the non-
volatile memory when you are done configuring.
Cancel Click Cancel to reset the fields to your previous configuration.
Clear Click Clear to return to the previous screen.
Table 161
Profile > VDSL2 > LineProfile > Rate Adaptive (continued)
LABEL DESCRIPTION