DS1 link performance measurements

Last Updated : Apr 29, 2024 |
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The DS1 Link Performance Measurements Summary and the DS1 Link Performance Measurements Detailed Log reports provide the performance measurements for the DS1 links.
The conventional error measurements used the Bit Error Rate parameter to describe the quality of digital transmission facilities. The DS1 links provide error bursts instead of single bit errors. Therefore, the operational characteristics of the DS1 links more accurately described by the Errored seconds, the Bursty errored seconds, the Severely errored seconds, and the Failed seconds.
The DS1 link performance is based on the number of error events that occur per second. The following are the types of error events:
  • Misframe: An erroneous bit pattern in a frame.
  • Slip: The deletion or repetition of a frame. This event occurs because of improper synchronization.
  • Extended Superframe Format (ESF) 6-bit Cyclic Redundancy Check (CRC-6): A data communication error over the DS1 link using the ESF format. This event occurs because of a mismatch between the calculated CRC-6 character appended to the transmitted data and the CRC-6 character recalculated by the receiver.
The DS1 link performance is measured using the following types of data:
  • Errored second: A second that contains one or more error events.
    The percentage of Error Free Seconds (%EFS) is calculated as:
  • Bursty errored second: A second that contains 2 to 319 error events.
  • Severely errored second: A second that contains 320 or more error events.
  • Failed second: An event of 10 or more consecutive Severely errored seconds. A Failed second event is cleared when no Severely errored seconds are detected for a period of 10 seconds.
  • Controlled slip second: A second with one or more controlled slips.
  • Loss of Frame count: The number of times a loss of frame is detected. The loss of frame is a continuous loss of signal or an out-of-frame condition for more than 2.5 seconds.
Note:
The Failed second event or the Severely errored second event usually results in a serious impact on the applications of the customer.
If the misframe or slip errors become severe, an alarm is raised. The rate at which the errors occur determines whether the alarm is minor or major. The maintenance for Communication Manager identifies the procedures that the maintenance personnel must perform to resolve the alarms.
The error event data is available for up to 24 hours in 15-minute increments. The measurement data older than 24 hours is overwritten by the current measurement data.
A system reboot from the tape clears the error event counters. To clear the DS1 error event counters, use the clear measurements ds1 log MedMod command, where Med is the media gateway number, Car is the carrier number, and Mod is the module number. For more information, see Avaya Aura® Communication Manager Hardware Description and Reference
Related links
DS1 Link Performance Measurements Summary reportDS1 Link Performance Measurements Detailed Log report