VeEX UX400, Руководство пользователя

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7.2.7.2 Evaluation According to ITU-T G.826
G.826 recommendation makes provision for higher bit rates and allows in-service measurement using the evaluation of block errors.
The following are evaluated: ES, SES, BE, BBE, and UAS.
Pass/Fail result depends on path allocation of 0.1 to 100%.
In-Service Measurement (ISM):
Simultaneous in-service measurement of “near end” and “far-end” of a selected path.
Out-of-Service Measurement (OOS):
Out-of-service measurement using bit errors in a test pattern.
Definitions:
Errored Second (ES):
A one-second time interval containing one or more errored blocks.
Severely Errored Second (SES):
A one-second time interval in which more than 30% of the blocks are errored
Block Error (BE):
A block containing one or more errored bits.
Background Block Error (BBE):
An errored block that is not a SES.
Unavailable Second (UAS):
A circuit is considered to be unavailable from the first of at least ten consecutive SES. The circuit is available from the first of at least ten
consecutive seconds which are not SES.
Note: The recommended measurement time for G.821 and G.826 is 30 days.
G.826 Analysis
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7.2.7.3 Evaluation According to ITU-T G.828
G.828 provides a precise block length for each bit rate as opposed to G.826.
ES, SES, BBE, UAS and SEP are evaluated.
Pass/Fail result is in conjunction with path allocation between 0.1 and 100%.
UX400 10G e-Manual D07-00-058P RevA00 Page 134 of 209