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noise. The SNR Margin is the amount of increased noise that can be tolerated while maintaining the
designated BER (bit error rate). The SNR Margin is set by Central Office DSLAM. If the SNR Margin is
increased, bit error rate performance will improve, but the data rate will decrease. Conversely, if the SNR
Margin is decreased, bit error rate performance will decrease, but the data rate will increase.
Line Attenuation: Attenuation is the decrease in magnitude of the ADSL line signal between the
transmitter (Central Office DSLAM) and the receiver (Client ADSL Bridge/Router), measured in dB. It is
measured by calculating the difference in dB between the signal power level received at the Client ADSL
Bridge/Router and the reference signal power level transmitted from the Central Office DSLAM.
Errored Seconds: During Showtime, if any given second contains a CRC error, then that second will be
declared and recorded as an Errored Second.
Loss of Signal: Loss of signal refers to the ADSL Bridge/Router losing an ADSL signal, not the computer
losing a signal with the modem. Loss of Signal event is only recorded if the signal is lost while the ADSL
Bridge/Router is in showtime status. This field displays the count of ADSL signal loss events.
Loss of Frame: A frame is a unit of data in ATM. This field displays the count of ADSL frame loss events. A
Loss of Frame event is only recorded if the signal is lost while the ADSL Bridge/Router is in showtime
status.
CRC Errors: Cyclic Redundancy Check (CRC) is a method for checking errors in data transmissions. This
field displays the number of transmit data frames containing CRC errors.
Data Rate: This field displays the ADSL data rate in kbps.
Latency: Latency, synonymously delay, is the amount of time it takes for a packet of data to get from one
designated point to another. This field displays the two mapping modes for latency (fast and interleaved).
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