Zyxel VES-1616FE-55A [124/318] Xdsl line data screen

Zyxel VES-1616FE-55A [124/318] Xdsl line data screen
Chapter 15 xDSL Line Data
VES-1616FE-55A User’s Guide
124
15.2 xDSL Line Data Screen
This screen displays an xDSL port’s line bit allocation.
Discrete Multi-Tone (DMT) modulation divides up a line’s bandwidth into tones. This screen
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 xDSL
transmission rates, and possibly to determine whether certain specific types of interference or
line attenuation exist.
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.
Down/up Stream
Noise Margin
These are the DSL line’s downstream and upstream noise margins. Measured
in decibels (dB).
Down/up Stream
Attenuation
These are the reductions in amplitude of the downstream and upstream DSL
signals. Measured in decibels (dB).
Down/up Stream
Attainable Rate
These are the highest theoretically possible transfer rates (in Kbps) at which the
port could send and receive data.
Info
Service Mode This field displays the VDSL or ADSL standard that the port is currently using.
Trellis Encoding This field displays whether Trellis encoding is turned on or off. Trellis encoding
helps to reduce the noise in xDSL transmissions. Trellis may reduce throughput
but it makes the connection more stable.
A
Down Stream
Interleave Delay
This field displays the number of milliseconds of interleave delay for
downstream transmissions.
Up Stream
Interleave Delay
This field displays the number of milliseconds of interleave delay for upstream
transmissions.
Down Stream
Output Power
This field displays the amount of power that this port is using to transmit to the
subscriber’s xDSL modem. The total output power of the transceiver varies with
the length and line quality. The farther away the subscriber’s xDSL modem or
router is or the more interference there is on the line, the more power is needed.
Up Stream
Output Power
This field displays the amount of power that the subscriber’s xDSL modem or
router is using to transmit to this port. The total output power of the transceiver
varies with the length and line quality. The farther away the subscriber’s xDSL
modem or router is or the more interference there is on the line, the more power
is needed.
Down Stream
Inp
This field displays the number of impulse noise protection DMT symbols in
downstream transmissions.
Up Stream Inp This field displays the number of impulse noise protection DMT symbols in
upstream transmissions.
Info xtur
Info xtuc
The Info xtur fields show data acquired from the xTUR (xDSL Termination Unit
– Remote), in this case the subscriber’s xDSL modem or router, during
negotiation/provisioning message interchanges. This information can help in
identifying the subscriber’s xDSL modem or router.
The Info xtuc fields show data acquired from the xTUC (xDSL Termination Unit
– Central), in this case VES-1616FE-55A, during negotiation/provisioning
message interchanges.
A. At the time of writing, the VES-1616FE-55A always uses Trellis coding.
Table 30 xDSL Line Rate Info (continued)
LABEL DESCRIPTION

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