A. CLI Command Descriptions
A-22
July
2002
4800-A2-GB20-10
SNR Margin (DSL Interfaces)
SNR (Signal-to-Noise Ratio) is the amplitude of the desired signal compared to the
amplitude of noise on the line. Margin is the amount of noise that can be tolerated
before a communication error or link establishment failure occurs. There are three
settings in the BitStorm 4800 related to SNR margin:
min-snr-margin
target-downstream-margin
target-upstream-margin
If behavior is set to adaptive, the target-downstream-margin and
target-upstream-margin settings determine the highest rates the modems can train
to. These rates may be less than the maximum configured rates.
For example, if target-downstream-margin is set to 6, the modems will train
(establish communication) at the highest rate downstream at which there is at
least 6 dB of margin, or, if it is lower, the maximum configured rate
(max-downstream-speed, in this case).
If behavior is set to fixed, the target margins determine the acceptability of the
signal at the selected fixed rate. If the margin is lower than the target margin at
that rate, the modems train again.
The min-snr-margin setting is for the upstream direction only. It causes the modem
to retrain if the margin falls and remains below the setting for 60 seconds.
Содержание BitStorm 4800 Express
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Страница 12: ...About This Guide x July 2002 4800 A2 GB20 10...
Страница 16: ...1 BitStorm 4800 Overview 1 4 July 2002 4800 A2 GB20 10...
Страница 20: ...2 Terminology and Conventions 2 4 July 2002 4800 A2 GB20 10...
Страница 32: ...4 Using the Web Interface 4 6 July 2002 4800 A2 GB20 10...
Страница 172: ...C MIB Support C 60 July 2002 4800 A2 GB20 10...
Страница 194: ...E CLI to MIB Object Cross Reference E 18 July 2002 4800 A2 GB20 10...
Страница 204: ...F Reference Tables F 10 July 2002 4800 A2 GB20 10...