摘要 |
A hierarchical protection switching framework uses detectors and protectors. A protector registers with a detector to receive notifications. A detector identifies a condition and the interested protector, and notifies the interested protector. The protector in response to the notification, typically either performs protection switching or notifies another protector of the condition. This protection switching is an extensible operation, and typically may include, but is not limited to switching traffic to a backup facility from a facility corresponding to the condition and switching traffic to a backup component from a component corresponding to the condition. The decision of a protector whether to notify another protector of the condition can be made based on different factors, such as, but not limited to a failure of the protection switching by the protector, a database lookup operation to identify whether notification of another particular condition has been received or not received, etc. |