Towards a Unified Network Slicing Model Mohammed Chahbar *§ , Gladys Diaz * and Abdulhalim Dandoush † * L2TI Laboratory, University of Paris 13, France § Ecole Nationale des Sciences Appliquées (ENSAO), Mohammed Premier University, Oujda, Morocco † ESME Sudria, Campus Paris-Sud, France Emails: mohammed.chahbar@edu.univ-paris13.fr, gladys.diaz@univ-paris13.fr, abdulhalim.dandoush@esme.fr Abstract—Network Slicing (NS) is actually an ongoing stan- dardization work, different visions and inconsistent use of termi- nologies are observed across Standard Developing Organizations (SDOs). In this paper, we aim at presenting and comparing most well known works about NS information models. The target is to combine major contributions from different SDOs and come out with a proposition of a unified NS model. The proposed NS model components and the way they relate to each other are then mapped to the end-to-end Management and Orchestration (MANO) reference architecture. Index Terms—network slicing, information model, data model, orchestration, network slice management I. I NTRODUCTION It is crucial to clarify the nuances around NS concepts from many standards associations as well as to combine and unify their works paving the way to researchers and developers for accelerating implementations and optimizing future propositions. In this work we first overview the different NS views and terminologies as introduced by the main SDOs, e.g., ETSI, IETF, GSMA and 3GPP (Section II). In particular, we want to explain their point of view regarding the Network Slice information model and to come out with a unified NS model (Section III). Second, we map the obtained slicing model along with its contained components and the way they relate to each other to the End-to-End MANO (Management and Orchestration) reference architecture [1] [2] proposed in the context of the 5G Exchange project [3] (Section III). II. OVERVIEW OF STANDARD NETWORK SLICE INFORMATION MODELS A. ETSI Information Model ETSI has identified a need for a standardized Network Slice architecture that illustrates the resource information flow over several technologies and administrative domains [4]. Then, it has provided a technology independent framework that de- scribes the main workflow steps from the tenant service order to slice deployment, monitoring and lifecycle management. Figure 1 depicts the ETSI reference Network Slice architecture and information model that consist of three Actor types: (i) Tenants that consume a service supported by a Network Slice instance. (ii) Network Slice Providers (NSPs) that provide access to Network Slice instances, and finally (iii) the Network Slice Agents (NSAs) that have the complete view and control of their own network infrastructure also called Subnet. Fig. 1. ETSI NGP reference Network Slice architecture and information model. The Network Slice deployment process begins with the ten- ant’s service order. A Service is defined in terms of a service profile that comprises a service graph and some additional service attributes. A service graph is the part that on one hand describes the required nodes in terms of compute, storage and service instance type such as firewall, load balancer, and router. On the other hand, it defines the service connectivity resources constraints also called edges such as link bandwidth, latency, and packet loss rate. Then, at the NSA level the "resource broker" component is in charge of gathering the complete domain-specific topology information. These topological data are then abstracted and exported to the resource database at the NSP domain. The Network Slice Instance (NSI) is an instantiation of the received service profile created by the NSP. It aims to compute the mappings of the service graph to the abstracted topological data stored in the resource database. Those mappings are then stored in the run-time service context object within the NSI. Figure 1 shows all the main information model entities involved in the Network Slice deployment process. Given that a Network Slice may span across several NSA domains, a Segment, is the set of paths and nodes a Network Slice instance is allocating to a specific NSA. Therefore, to continue the workflow process, the NSP delegates Segments to appropriate NSAs for deployment. Segments are then concate- 978-3-903176-24-9 © 2019 IFIP