Collaboration mechanism
The Track module collaborates with detection modules and application modules.
As shown in Figure 57, collaboration is enabled when you associate the Track module with a detection module and an application module, and it operates as follows:
The detection module probes specific objects such as interface status, link status, network reachability, and network performance, and informs the Track module of detection results.
The Track module sends the detection results to the application module.
When notified of changes for the tracked object, the application modules can react to avoid communication interruption and network performance degradation.
Figure 57: Collaboration through the Track module
Collaboration between the Track module and a detection module
The detection module sends the detection result of the tracked object to the Track module. The Track module changes the status of the track entry as follows:
If the tracked object operates correctly, the state of the track entry is Positive. For example, the track entry state is Positive in one of the following conditions:
The target interface is up.
The target network is reachable.
If the tracked object does not operate correctly, the state of the track entry is Negative. For example, the track entry state is Negative in one of the following conditions:
The target interface is down.
The target network is unreachable.
If the detection result is invalid, the state of the track entry is NotReady. For example, the track entry state is NotReady if its associated NQA operation does not exist.
Collaboration between the Track module and an application module
The track module reports the track entry status changes to the application module. The application module can then take correct actions to avoid communication interruption and network performance degradation.