SMC Networks BARRICADE SMC7901WBRA2 B1 User Manual

Page 54

HAPTER

| Status Information

DSL Statistics

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The following items are displayed on this page:

◆

Mode — Displays the connection mode for the ADSL Router, which is

fixed at ADSL2+.

◆

Latency — Displays the hop-count - the number of routers your

packets must navigate before they reach the destination.

◆

Trellis Coding — Displays Trellis modulation (also known as trellis

coded modulation, or simply TCM) - a modulation scheme which allows

highly efficient transmission of information over band-limited channels

such as your telephone line.

◆

Status — Displays the ADSL connection status (“activating”, “up” or

null).

◆

Power Level — Displays the power level employed for ADSL port

filtering.

OWNSTREAM

PSTREAM

Refers to statistics either downloaded or uploaded from the ADSL Router

◆

SNR Margin (dB) — Displays the current signal-to-noise margin

expressed in decibels (dB). SNR is the ratio of signal power to the noise

power corrupting the signal.

◆

Attentuation (dB) — Displays the amount of attenuation in signal

strength due to conductive losses in transmission medium. Attenuation

affects the propagation of waves and signals in electrical circuits,

expressed in decibels (dB).

◆

Output Power (dBm) — Displays the current input/output power at

the ADSL Router’s DSL interface, expressed in decibels (dB) of the

measured power referenced to one milliwatt (mW).

◆

Attainable Rate (Kbps) — Displays the maximum attainable payload

on the downstream and upstream channels, expressed in kilobits per

second.

◆

Rate — Displays the actual payload carried on the downstream and

upstream channels.

◆

K (number of bytes in DMT frame) — Displays the number of bytes

in a DMT frame. DMT (discrete multi-tone modulation) - is a frequency-

division multiplexing (FDM) scheme utilized as a digital multi-carrier

modulation method.

◆

R (number of check bytes in RS code word) — Displays the

number of redundancy bytes used for error correction. Redundancy bits

are the number of bits used to transmit a message minus the number

of bits of actual information in the message.