This field, which appears under the ‘Alarm settings’ tab of a Service definition, is used to select the names of the contact groups that should be notified whenever there are problems with this service.
If you have manually created a new ‘Service” entry, then this field will be empty and you must specify at least one contact and/or contact group in each service definition.
Note: By default, every existing service template will have, depending of the type of service, a predefined contact group selected.