ZyXEL Communications VES-1124 -, User Manual

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VES-1124 User’s Guide
6-14 Basic Setting
The VES determines line quality using the Signal-to-Noise Ratio (SNR). SNR is the ratio of the amplitude of the
actual signal to the amplitude of noise signals at a given point in time. A low SNR indicates poor line quality.
Select Fixed Rate to disable transmission rate adjustment. If the attainable speeds cannot match configured speeds,
then the VDSL link may go down or link communications may be sporadic due to line errors and consequent
retransmissions
Select Rate Adaptive Decrease Mode to enable the VES to adjust to a new lower rate when the line quality
deteriorates until the connection is broken. The VES will re-establish the line connection when the line quality
improves. However, the new line rate might be lower that the configured line rate.
6.10 VDSL Common Setup
To configure general VDSL port settings, click Basic Setting and VDSL Common Setup to display the screen as
shown next.
Figure 6-5 VDSL Common Setup
The following table describes the labels in this screen.
Table 6-6 VDSL Common Setup
LABEL DESCRIPTION
Band Plan Use the radio button to select a band plan.
PBO PBO (Power Back Off) allows the switch to provide better service in a network environment with
cables of varying lengths.
Select Enable to activate this function.
Apply Click Apply to save your changes back to the switch.
Cancel Click Cancel to begin configuring this screen afresh.
6.11 VDSL Profile Setup
A profile is a table that contains a list of pre-configured VDSL settings. Each VDSL port has one (and only one)
profile assigned to it at any given time. The profile defines VDSL parameters such as the payload rates. You can
configure multiple profiles, including profiles for troubleshooting.