Upstream Power Back Off; Rfi (Radio Frequency Interference); Downstream And Upstream; Dsl Profiles - ZyXEL Communications MSC1000G User Manual

MSC1000G User's Guide

10.2.2 Upstream Power Back Off

PSD (Power Spectral Density) defines the distribution of a VDSL line's power in the
frequency domain.
In a network with varying telephone wiring lengths, the PSD on each line is different. This
causes crosstalk between the lines. Enable Upstream Power Back Off (UPBO) to allow the
system to adjust the transmit PSD of all lines based on a reference line length so that the PSD
at the receiving end is the same.

10.2.3 RFI (Radio Frequency Interference)

RFI is induced noise on the lines by surrounding radio frequency electromagnetic radiation
from sources such as AM and HAM radio stations. Since VDSL uses a much larger frequency
range that overlaps with other radio frequency systems, signals from VDSL lines and other
radio systems interfere with each other. To avoid performance degradation due to RFI, set the
switch to not transmit VDSL signals in the RFI band defined by the regulatory bodies (ETSI
and ANSI). You can also configure your own RFI bands on the system.

10.3 Downstream and Upstream

Downstream refers to traffic going out from the line card to the subscriber's DSL modem or
router. Upstream refers to traffic coming into the line card from the subscriber's DSL modem
or router.

10.4 DSL Profiles

A DSL profile is a table that contains a list of pre-configured DSL settings. Each DSL port has
one (and only one) profile assigned to it at any given time. You can configure multiple
profiles, including profiles for troubleshooting. Profiles allow you to configure DSL ports
efficiently. You can configure many DSL ports with the same profile, thus removing the need
to configure the settings of each DSL port one-by-one. You can also change an individual DSL
port's settings by assigning it a different profile.
For example, you could set up different profiles for different kinds of accounts (for example,
economy, standard and premium). Assign the appropriate profile to an DSL port and it takes
care of a large part of the port's configuration. You still get to individually enable or disable
each port and configure port specific settings. See the chapter on profiles for how to configure
DSL profiles.
126 Chapter 10 DSL Port Setup Screens