A network slice managing entity, comprising means configured to obtain a service request for a network slice, the service request defining service requirements; request network slice descriptions from a database and selecting at least one network slice which support said service requirements according to the descriptions; generate a resource graph comprising nodes representing infrastructure resources and links representing connections between the nodes, the resource graph depicting resources needed for providing the service, wherein the generating is carried out based on a network slice description of the selected at least one network slice; transmit the resource graph to an infrastructure manager for mapping a topology of said network infrastructure onto said resource graph and determining at least one subset of said network infrastructure; and, receive a mapping result from said infrastructure manager containing said at least one subset of said network infrastructure.