ZyXEL Communications IES-2000, User Manual

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IES-2000/3000 User’s Guide
System Maintenance 1 24-5
Table 24-2 Port Statistics
FIELD DESCRIPTION
TxOctetsLSB Lower 32-bit count of the number of transmitted octets of data (including those in bad
frames).
RxFragments This is the number of frames received that were less than 64 octets long and with either a
CRC error or an alignment error.
RxJabbers This is the number of frames received that were greater than the maximum octets
(specified for the system by the configuration software) long and with either a CRC error
or an alignment error.
RxAlignErrors This is the number of frames received that were of the proper size but with a CRC error
and non-integral number of octets.
RxSymbolErrors This is the number of frames received that were of the proper size but experienced
symbol error during frame reception.
SecurityDrops This is the number of good frames that were dropped because the violation of the switch
security rules.
VLANDrops This is the number of good frames that were dropped because the specified destination
port does not belong to the VLAN domain.
UndersizedPkt This is the number of frames received that were less than 64 octets long and without any
CRC or alignment errors.
OversizedPkt This is the number of frames received that were greater than the maximum octets
(specified for the system by the configuration software) long and without any CRC error or
alignment errors.
TxOversizePkt This is the number of frames transmitted that were greater than the maximum octets
(specified for the system by the configuration software) long and without any CRC or
alignment errors.
VDSL
Upstream/Downstream
status The following parameters apply to both upstream and downstream VDSL.
Constellation Constellation shows the modulation method and speed. The constellations are QAM 4,
QAM 8, QAM 16, QAM 64, QAM 256 where QAM (Quadrature Amplitude Modulation)
defines how many bits there are per symbol; for example QAM 4 means 2 bits per symbol
(2
2
), QAM 8, 3 bits (2
3
) per symbol and so on.
Int (Interpolation) defines how fast the symbols go through the line. It is equal to 25.0MHz
/ baud rate, so for example, Int 8 = 25.0 / 8 Mbaud.
Rate This is the VDSL raw speed.
Fc This is the carrier frequency
SNR The higher the SNR (Signal-to-Noise Ratio) number, the better. SNR (Signal-to-Noise
Ratio is the ratio of the amplitude of the desired signal to the amplitude of noise signals at
a given point in time.
MSE Minimum Square Error. The minimum mean-square error (also known as MMSE)
performance measure is a popular metric for optimal signal processing.
RS_ERR This is the Reed-Solomon error count. Reed-Solomon codes are block-based error
correcting codes and are used to correct errors in many systems including
PSD This is the Power Spectrum Density.
DISC This is a VDSL Disconnect counter.