Model

A model must be specified such that nodes speak a common language. Cisco has developed the identity model to be used in the context of security products, supported by the Identity Services Engine (ISE). The identity model will look very different from a model used in a different context. However, all models extend core elements provided by pxGrid. A model defines one or more entities, relationships between entities, and interfaces for invoking functionality. The identity model defines entities such as Session, User, and PostureAssessment as these concepts relate to the identity services space. It further establishes that a Session contains one User and one or more PostureAssessments. A model also defines one or more interfaces. Interfaces establish a contract between a consumer and a provider of information. The identity model defines interfaces such as getSessionByIPAddress and getSessionByMacAddress.

An information channel or topic for sharing contextual information is referred to as a capability. A model defines the capability, context data and interfaces or operations allowed on the capability. A model can define multiple capabilities. In the identity model, the session directory capability consists of interfaces for consuming information related to session logins in a network.