## 3 Synopsis of KDN Paradigm
### Detailed KDN Architecture
#### 3.2.2 Management/Administration/Measurement Layer  
As illustrated in Figure 7, the administration layer, which runs concurrently alongside the KDN control layer, carries out the functions of data or information accumulation through the network equipment, network component monitoring, and network instrument configuration. Additionally, the management layer in KDN may be impacted from the knowledge layer in assisting with actual-time network surveillance as well as from the application layer in implementing setup guidelines, in which monitoring results can help with dynamically setting the network [155, 159]. An encapsulation of network services is the network-service abstraction sub-layer that encapsulates services including load balancing, intrusion detection, fault management, etc., serves as a bridge for control and administration choice-making programs to link with control and administration layers [183]. Moreover, network data needed for network surveillance in the management layer and knowledge creation in the knowledge layer are stored and managed in the Management Information Base (MIB).  
Due to its compatibility with OpenFlow-based forwarding devices, the OpenFlow management-and-CONFIG Protocol (OF-CONFIG), which transports data via the NETwork-CONFIG Protocol (NETCONF), is the most frequently used network setup and management protocol [184]. Likewise, OF-CONFIG or NETCONF can be replaced with the Simple-Network-Management Protocol (SNMP), a protocol that has been developed for the surveillance and setting up of network gadgets in KDN [185]. Moreover, Complexity-Oblivious Network-Management (CONMan) [186] and Platform for Automated-Operation and Configuration-Management (PACMAN) [187] are two other alternative network management frameworks that can be utilized in KDNs. These frameworks provide the combined tasks of network surveillance and configuration as network management tasks.  
There have been frameworks proposed only for the task of network surveillance. Network surveillance frameworks such as Payless [188], joint HOst-NEtwork (HONE) [189], OpenNetMon [190], and OpenSample [191] have been utilized for network surveillance by collecting traffic statistics data and QoS data.  
It should be noted that the administration layer can gather facts for network setup (configuration data) and network surveillance (traffic statistics, network layout, metrics of performance, etc.) utilizing a protocol like SNMP/OF-CONFIG or a network surveillance platform. Additionally, other data can be gathered using a Data Gathering Method (DGM), like quadratic integer programming-based optimization [192], packet sampling [193], adaptive data collection [194], and sensor measurement collection [195]. Additionally, the management layer may gather a variety of data, including layout, setting up, traffic patterns, records of events, consumption of resources, indicators of performance, information from sensors, etc.  
A representation language called Yet Another Next-Generation (YANG) has been employed to represent the setups and state information of network gadgets [196]. As an alternative, the Common-Information Model (CIM) is a model of data that provides a consistent method of displaying data regarding instrument functionalities and network architecture [197]. It should be noted that data inside the MIB of the administration layer can be represented using both YANG and CIM data representations.