The HasLowerLayerInterface ReferenceType is a concrete ReferenceType and can be used directly. It is a subtype of HierarchicalReferences ReferenceType.

The usage of the References is following the YANG modelling approach which is using reference pointers in the YANG-interface nodes to point to other interface nodes in lower or higher layers (“lower-layer-if”, “higher-layer-if”). The YANG Data Model for Interface Management is defined in IETF RFC 8343.

Virtual interfaces shall reference their physical interfaces with the HasLowerLayerInterfaceReferenceType. Annex A contains examples for such hierarchical references.

The SourceNode of this ReferenceType shall be an Object organized in the NetworkInterfaces folder.

The TargetNode of this ReferenceType shall be an Object organized in the NetworkInterfaces folder.

The HasLowerLayerInterface ReferenceType is formally defined in Table 76.

Table 76 – HasLowerLayerInterface definition

Attributes	Value
BrowseName	HasLowerLayerInterface
InverseName	HasHigherLayerInterface
Symmetric	False
IsAbstract	False
References	NodeClass	BrowseName	Comment
Subtype of the HierarchicalReferences ReferenceType defined in OPC 10000-5
Conformance Units
BNM IETF Interface Base Info