# A Comprehensive Survey on Knowledge-Defined Networking
## 4 Management Plane
### Network Data Collection
#### 4.5.2 Types of Data  
The management plane collects data to gain insight into the behavior of the network and its users in order to make decisions about network configuration and optimization. The management plane may collect different types of data related to network management from the infrastructure plane. The data collected and stored in the management plane is the basis for knowledge generation. Different types of data, such as topology, configuration, traffic flow, event logs, resource usage, performance metrics, sensor data, etc., can be collected by the management plane.  
It can collect configuration data related to the configuration of the network devices, such as the operating system, device name, network interface addresses, routing protocols, security settings such as access control lists, and quality of service settings [265]. The collection of configuration data is useful for configuring the network using the management plane.  
Further, the management plane may collect devices' resource usage data, such as CPU utilization, memory utilization, network interface statistics, etc., in order to identify potential performance issues and optimize network performance [266].  
In addition, the management plane can collect data about network traffic flow, including the source and destination of traffic, the amount of traffic, and the protocols used, in order to form a global-level traffic matrix at the management plane [267]. These data can be used to identify patterns in network usage and can be further analyzed using the knowledge plane for energy management, mobility management, and fault management. For instance, network traffic data can be analyzed to identify usage patterns of energy consuming devices to aid in optimizing energy usage and facilitate proactive maintenance of network infrastructure by identifying potential failures. Note that network traffic flow data are collected jointly by the control and management planes.  
Further, the management plane may collect event logs, which include information about the events that occur in the network, such as system errors, security alerts, configuration changes, etc. [268]. These event logs can be used for network troubleshooting.  
Another piece of data that can be jointly collected by both the management and control planes is the network topology information, which includes the location of the switches, routers, and other network devices in order to develop a global view of the network [269].  
Furthermore, the management plane may collect data from sensors such as temperature, pressure, humidity, etc. for real-time predictive fault diagnosis of communication infrastructure [67].  
The management plane monitors and allocates resources for network devices. Specifically, the management plane involves fault, mobility, and energy management. Thus, it collects performance metrics such as energy consumption, device mobility metrics (position, velocity, acceleration), and device availability/failure rate [270].  
Furthermore, the management plane can collect configuration policies and monitoring policies related to monitoring tasks for device energy management, mobility management, fault management, and configuration tasks in order to verify the policies. Monitoring policies usually involve policies for resource allocation, troubleshooting, and analysis [271].