In computer networking and computer architecture, a northbound interface of a component is an interface that conceptualizes the lower level details (e.g., data or functions) used by, or in, the component. It is used to interface with higher level layers using the southbound interface of the higher level component(s). In architectural overview the northbound interface is normally drawn at the top of the component it is defined in, hence the name northbound interface.
A southbound interface decomposes concepts in the technical details, mostly specific to a single component of the architecture. Southbound interfaces are drawn at the bottom of an architectural overview.
Northbound interfaces normally talk to southbound interfaces of higher level components and vice versa.
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