ZyXEL Communications P8802T User Manual page 70

Chapter 3 Device Info Screens
Table 8 xDSL Statistics Screen (continued)
LABEL
Upstream
Line Coding
(Trellis)
SNR Margin
(0.1 dB)
Attenuation
(0.1 dB)
Output Power
(0.1 dBm)
Attainable Rate
(Kbps):
Rate (Kbps)
Super Frames
Super Frame
Errors
RS Words
RS Correctable
Errors
RS
Uncorrectable
Errors
HEC Errors
OCD Errors
LCD Errors
Total Cells
Data Cells
Bit Errors
Total ES
Total SES
Total UAS
xDSL BER Test
Reset Statistics
70
DESCRIPTION
These are the statistics for the traffic direction going out from the port to the service
provider.
This displays whether or not the port is using Trellis coding for traffic. Trellis coding helps to
reduce the noise in ADSL transmissions. Trellis may reduce throughput but it makes the
connection more stable.
This displays the Signal-to-Noise Ratio margin (in 0.1 dB). A DMT sub-carrier's SNR is the
ratio between the received signal power and the received noise power. The signal-to-noise
ratio margin is the maximum that the received noise power could increase with the system
still being able to meet its transmission targets.
This displays the line attenuation, measured in tenths of a decibel (0.1 dB). This attenuation
is the difference between the power transmitted at the near-end and the power received at
the far-end. Attenuation is affected by the channel characteristics (wire gauge, quality,
condition and length of the physical line).
This displays the far end actual aggregate transmit power (in dBm). Downstream is how
much port the service provider is using to transmit to the port. Upstream is how much
power the port is using to transmit to the service provider.
These are the highest theoretically possible transfer rates at which the port could send and
receive data.
This displays the data transfer rates at which the port is receiving and sending.
This displays the number of ADSL superframes the DSL connection received and
transmitted. Each superframe contains 68 ADSL data frames and a one-frame synch symbol
for a total number of 69 frames.
This displays the number of errored ADSL superframes the DSL connection received and
transmitted.
This displays the number of Reed Solomon error correction words for received and
transmitted traffic.
This displays the number of errored packets corrected by Reed Solomon error correction for
received and transmitted traffic.
This displays the number of errored packets that Reed Solomon error correction could not
correct for received and transmitted traffic.
Header Error Control (HEC) checks for errors in packet headers.
The number of Out of Cell Delineation errors for received and transmitted traffic. An OCD
error means seven consecutive ATM cells had Header Error Control (HEC) violations.
The number of Loss of Cell Delineation errors for received and transmitted traffic. An LCD
state means an OCD condition persisted for 4 milliseconds.
This displays the total number of DSL cells including headers.
This displays the number of data payload DSL cells, excluding headers.
This displays the number of errored bits.
This displays the number of Errored Seconds meaning the number of seconds containing at
least one errored block or at least one defect.
This displays the number of Severely Errored Seconds meaning the number of seconds
containing 30% or more errored blocks or at least one defect. This is a subset of ES.
This displays the number of UnAvailable Seconds.
Click this to open a screen where you can perform a ADSL Bit Error Rate (BER) test to
determine the quality of the ADSL connection.
Click this to clear the screen's statistics counters.
Basic Home Station VDSL2 P8802T User's Guide