User guide

Video Services provided by ADSL Software Engineering
Telesyn Service Guide (Optimizing Video Services)
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3.2.5.2 ADSL Loop Quality Audit
Without this audit, an ADSL port would detect a Loss of Link and would try to re-enable the link. In applications
such as video, however, a degradation (rather than a loss) of the loop quality could still make the video unusable.
With this audit, whenever an ADSL loop experiences a degradation in quality (high Errored Seconds) it will be
detected by the audit and the port will be disabled and enabled to retrain the link.
3.2.5.2.1 Setting the Level of the Audit
Note: To change the level, the port must be disabled.
There are three levels of audit, as described here.
3.2.5.3 ADSL Interface Monitoring
The following thresholds and counters are especially important to monitor the port for problems or potential
problems.
3.2.5.3.1 Errored Seconds
The Errored Seconds statistic is monitored by the Loop Quality Audit. When the ES is being monitored and the
audit has had to retrain the ADSL port, the viewing of the statistic should show the ES rate increasing for a
period and then returning to an acceptable number as a result of the retraining of the port.
TABLE 3-5 Levels of Testing for the Loop Audit
Level Audit Activities
OFF
This setting is for test purposes only. The audit is deactivated, ADSL link quality is not monitored,
automatic port retrains are not performed (e.g., due to loss of connection). The line must be manually
retrained via disable port/enable port.
Note: This setting is for test purposes only.
LOW
The ADSL port will be monitored for catastrophic events such as “loss of link” and bit error rates
greater than allowed under TARGETSNRMARGIN. The port will automatically retrain due to such
events, and a Port Quality Retrain log is produced.
MEDIUM In addition to LOW:
The ADSL port will be monitored for bit error rates that effect video quality. The port will be auto-
matically retrained, and a Port Quality Retrain alarm and log are produced.
HIGH In addition to MED:
The ADSL port will be aggressively monitored for bit error rates that effect video quality. The port
will be automatically retrained, and a Port Quality Retrain alarm and log are produced.