Yoopl supports optional escalation of contact notifications for hosts and services. Escalation of host and service notifications is accomplished by defining host escalations and service escalations in your settings.
Once a notification is escalated, the contact/groups and notification options for the object will be overridden by the escalation's settings.
When Are Notifications Escalated?
Notifications are escalated if and only if one or more escalation definitions matches the current notification that is being sent out. If a host or service notification does not have any valid escalation definitions that applies to it, the contact group(s) specified in either the host group or service definition will be used for the notification.