Propagating proactive alarms up the topology tree reduces the number of alarms by grouping together alarms, based on network topology associations within an Optical Node when measuring Upstream FEC & Upstream SNR threshold breaches. You can configure the minimum percent of children with the same issue type and frequency required to propagate an alarm, based on the size and network element type (fiber node, amplifier, splitter, tap, service location).
Propagating proactive alarms can increase efficiency. Without propagation, multiple alarms can be created for one issue, causing increased triage and analysis time. Also, the severity of an alarm can be diluted because many small alarms remain identified as separate issues. A single modem or channel reading can alter the topology of the alarm issue, often breaking the alarm into multiple alarms when the human eye would render a different conclusion.
Example
Consider the following example of the benefit of propagating proactive alarms.
Without propagation, two alarms are issued, as shown in the following diagram.
With a propagation threshold of 66 percent, only one alarm is issued for the same number and placement of problematic nodes, as shown in the following diagram.
Adding propagation rules to proactive alarms can combine multiple small alarms into one larger alarm.
Configuration
Propagation alarms can be configured for the following metrics:
- SC-QAM
- Upstream SNR
- Upstream SNR Deviation
- Upstream CER
- Upstream CCER
- OFDMA
- MER Deviation
- MER Percentile Value
- Mean MER
- Upstream CER
- Upstream CCER
Propagation percentages are configured in the Issues Propagation tab of the Fiber Node Proactive Profiles section of the Configuration module. See the ServAssure® NXT Administration Guide for details.