Configuring Thresholds and Incidents › What are Call Server and Call Server Group Thresholds? › Call Server Group Thresholds

Call Server Group Thresholds

The call server group thresholds are designed to be applied to your call server clusters, or to other logical groupings of call servers. Each call server in a cluster can play several different roles to provide failover safeguards and load balancing. The call server group thresholds apply to all call servers in a cluster.

The default call server group threshold triggers incidents when phone status changes exceed the Phone Status Changes metric. The Phone Status Changes incident helps you detect failover events and branch office outages. The incident also helps identify call server performance issues and costly branch office connectivity failures. Typically, the incident itself provides enough information to help you identify the affected devices and call server group. The Phone Status Changes incident helps you distinguish endpoints that access call servers over a WAN link from other endpoints that use a local cluster.

Default: The default call server group threshold is 50 percent of all devices that had status changes during the reporting interval.

The following types of status changes contribute to a Phone Status Changes incident.

Currently Missing Phones status

The percentage of endpoints that were registered to a server in the group, but are no longer registered to any server in the group. The total does not include endpoints that had normal deregistration, which may have occurred as part of a restart.

Recently Moved Phones status

The percentage of endpoints that were registered to a call server in this group, but are now registered to a different call server in the same group.

New/Found Phones status

The percentage of endpoints that are registered to a call server in this group, but were not registered during the previous reporting interval.

• A new endpoint has never registered to this call server group since monitoring with UC Monitor began.
• A found endpoint lost contact with this call server group in the past, but registered again with the group during the last reporting interval.

When the threshold is exceeded, a Phone Status Changes incident is included in the summary list of Call Server incidents. Separate data views provide information about each type of status change when you drill down into the detailed incident report.

The incident is not dependent on the similar information reported in the Phones Report. For example, when a Currently Missing Phones status change occurs, multiple devices in the Phones List can show a status of Unavailable or Lost Contact. The status of an endpoint is actually the device status at the end of the reporting interval. When a change in status occurs, the incident is created before another status change occurs. The later status is reflected in the Phones Report and is slightly out of sync with the incident. Review the Phone Details Report, which includes the Previous Status for each endpoint.