Abstract: This invention concerns an arrangement for identifying a data model of at least one service (2103, 2104, 2105), the arrangement comprises a discovery service (2106), comprising storage means for storing data models of the at least one service and for storing a relationship between the data models, and the arrangement comprises inspection means for gathering data models of a service and for establishing relationship between the data models and data models of the at least one service. The invention also concerns a data federation method for identifying a data model of at least one service, by inspecting a service and deriving a data model of the service, establishing a relationship between already known data models of the at least one service, and providing the data models of these services and the relationship between the data models.