Introduction

The DS1 Performance report measures the number of errors encountered over a selected time period.

DS1 links control communication between layers 2 and 3 devices, and should run error-free. Any errors on these links indicate either a configuration issue or fault exists. Errors can cause audio quality issues, but more importantly are often a precursor to a full outage of the DS1. Therefore early detection can lead to the prevention of an outage.

See below for and explanation of each measure that the report tracks.

Note: A blank report is good as it means there are no errors.

Uses

Use this report to:

  • Detect issues with speech quality (errors can cause clicks and static).
  • Detect and resolve issues before they become business-impacting.
  • Use for Root Cause Analysis (RCA) to prevent a recurrence of the incident.
  • Validate DS1 configuration.
  • Validate DS1 synchronize.

Example

The report below shows the various error types on a DS1 board.

The errors shown are of errored seconds (ES) and controlled slip (CSS) type, and occur at a regular intervals. This most likely indicates there is an issue with synchronisation settings.

Correction of this setting will improve voice quality on this circuit and will prevent an outage occurring if the respective clocks on each end of the circuit drift further apart.



Additional Information

DS1 link performance is measured by the following error event counts:

MeasureDescription
Errored Second (ES)Any second that contains one or more error events.
Bursty-Errored Second (BES)Any second that contains between 2 to 319 error events.
Severely-Errored Second (SES)Any second that contains 320 or more error events.
Failed Second (UAS/FS)

A state that exists when ten or more consecutive severely errored seconds are detected.

A Failed Second state is cleared when no severely errored seconds are detected for a period of 10 consecutive seconds.

Controlled Slip Second (CSS)Any second with one or more controlled slips (a replication or deletion of a DS1 frame by the receiver).
Loss of Frame Count (LOFC)The number of times a loss of frame is declared. A loss of frame is declared when there is a continuous loss of signal or out of frame condition for greater than 2.5 seconds.
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