Performance Monitoring Counters and Threshold Crossing Alerts
PM counters and TCAs can be used for identifying trouble and troubleshooting problems in ITU-T G.709
optical transport networks. ITU-T Recommendation M.2401 recommends that the following PM parameters
be monitored at the ODUk layer:
• SES (severely errored seconds)A one-second period that contains greater than or equal to 30 percent
errored blocks or at least one defect. SES is a subset of the errored second (ES) parameter, which is a
one-second period with one or more errored blocks or at least one defect.
• BBE (background block error counter)An errored block not occurring as part of an SES. BBE is a subset
of the errored block (EB) parameter, which is a block in which one or more bits are in error.
Different PM count parameters are associated with different read points in a network.
Monitoring Points on ONS DWDM, on page 29
illustrates the PM read points that are useful in identifying
DWDM circuit points of failure. The
document lists all PM parameters and provides
block diagrams of signal entry points, exit points, and interconnections between the individual circuit cards.
Consult these specifications to determine which PM parameters are associated with the system points you
want to monitor or provision with CTC or TL1. The monitoring points might vary according to your
configuration.
When LOS, LOS-P, or LOF alarms occur on TXP and MXP trunks, G709/SONET/SDH TCAs are suppressed.
For details, see the .
Note
Figure 10: Performance Monitoring Points on ONS DWDM
TCAs are used to monitor performance through the management interface by indicating whether preset
thresholds have been crossed, or whether a transmission (such as a laser transmission) is degraded. TCAs are
not associated with severity levels. They are usually associated with rate, counter, and percentage parameters
that are available at transponder monitoring points. The
document contains more
information about these alerts.
Select and complete the following procedures according to your network parameters.
Set Node Default BBE or SES Card Thresholds
Complete the following procedure to provision default node ODUk BBE and SES PM thresholds for TXP
cards.
Cisco NCS 2000 series Troubleshooting Guide, Release 11.0
29
General Troubleshooting
Performance Monitoring Counters and Threshold Crossing Alerts