ZyXEL VES1724-56 User Guide - Page 117

Chapter 9 VDSL Setup 9.3.6 VDSL Line Profile Setup > Virtual Noise Click the Modify link next to the Virtual Noise field in the VDSL Line Profile Setup screen to open the screen as shown next. Use the screen to configure VDSL virtual noise settings for a VDSL line profile. Figure 56 VDSL Virtual Noise Setup The following table describes the labels in this screen. Table 34 VDSL Virtual Noise Setup LABEL Virtual Noise Preview Downstream, Upstream DESCRIPTION This displays the virtual noise setting result in a graph. If there is too much noise on a line, the allowed line speed may be reduced or the line may not initialized. Virtual noise is the noise allowed on the line before the first line speed adjustment occurs. Switch then uses a lower data rate on tones which you added a noise level for the line initialization. A lower data rate increases a line's stability and avoid the line being easily dropped when actual noise occurs. Click this to update the virtual noise setting result according to your setting configured at the bottom of the screen. Select whether you want to enable virtual noise (Enable) or not (Disable) for downstream and upstream transmissions. Note: For a poor quality subscriber line, you should enable this and configure virtual noise on tones where noise may occur. Break Point Note: The higher the virtual noise, the lower the line speed. This index number identifies each incremental break point. VES1724-56 User's Guide 117