Declarative construction of knowledge graphs from NETCONF data sources

The knowledge graph paradigm is drawing attention in the network industry as a technology for integrating heterogenous data silos such as model-driven telemetry based on the YANG language. In this sense, declarative mapping languages have emerged as scalable and flexible solutions for constructing knowledge graphs. A prominent mapping language is the Resource Mapping Language (RML), which enables the integration of heterogenous data sources by reusing ontologies that describe access to them. However, when it comes to the network domain, there is a lack of ontologies that describe access to YANG data exposed by network devices. This paper introduces the YANG Server Ontology for describing YANG servers and the interactions with them using network protocols like NETCONF. Additionally, guidelines for reusing the ontology in RML mappings are provided and validated in a use case by extending a reference RML engine.