Abstract – Network virtualization introduces two concepts: slice (i.e., virtual network), which consists of virtual nodes and links, and slice developer, which is the third role in networks. Slice developers can introduce new network services by using slices. A method for introducing new types of virtual nodes and links for new services into the slicedefinition language and the virtualization infrastructure by evolving physical nodes (i.e., “virtualization nodes” or VNodes) is proposed. This evolution consists of two stages: the experimental stage and the operational stage. In the experimental stage, data and control plug-ins are developed and tested by the operator or vendor by using experimental sliver definitions. In the operational stage, which is focused on in this study, the plug-ins are integrated into original components in the infrastructure and are available for slice development by using normal sliver definitions. By mapping type names to plug-in identifiers and parameters, the proposed method enables abstract and simple definitions of slices by slice developers and authorization of plug-ins by the operator, but it remains the loose integration of the new function, i.e., the plug-in architecture used in the experimental stage. Prototyping and evaluation demonstrates that this method greatly simplifies both slice developers’ tasks and operators’ tasks.