Abstract

With the emergence of 5G, multiple vertical industries are seeking to leverage new type of services with stringent and diverse performance requirements. Monolithic network architectures do not allow for supporting efficiently such services at the same time. In this context, the network slicing paradigm was introduced to enable network operators to create multiple end-to-end logical networks, i.e. network slices (NwSs), on top of a common and shared physical infrastructure. Each NwS is customized to meet specific functional and non-functional requirements such as Quality of Services (QoS) and isolation requirements.
Intent-based networking is considered as one of the key paradigms to automate and reduce the complexity of managing multiple network slices with divergent requirements. An intent-based networking system should allow for expressing requirements, at a high level of abstraction without low level networking/resource details, and be able to translate these requirements into low-level and deployment related information. Applying the intent-based networking paradigm in the network slicing context will allow for the automation of its provisioning process starting from the preparation phase to the runtime phase.
In this thesis, we propose a model-driven approach to automate NwS design from tenant intents. The proposed approach consists of several steps and starts from intents expressed by the tenant (NSliceReq) and intents expressed by the operator. The NSliceReq expresses high-level requirements for communication services (CSs) and NwSs along with their non-functional required characteristics. The operator intents describe the slice types supported by the operator from a QoS perspective. The proposed approach starts by combining both intents in a consistent manner and identifying the NwSs to design and their characteristics as a set of combined intents solutions. In the next step, with the help of an ontology, the approach processes and decomposes each combined intents solution. This decomposition allows for enriching and propagating the isolation intents expressed, in the NSliceReq, for the NwS or its supported CSs. In order to select the appropriate VNFs and PNFs to compose the NwS, we start by assigning the placement constraints of the composing NFs of the required NwSs/CSs. To achieve this we take into consideration, during the design process, placement constraints originating from different sources, namely the tenant, the operator, the available VNFs/PNFs and the standards. The VNF and the PNFs are selected based on the decomposition information and the assigned placement constraints. Thereafter, the approach generates the forwarding graphs, the traffic flows and dimensions the selected VNFs/PNFs. In the following step, the approach performs the embedding of each forwarding graph according the QoS intents. We then use the embedding information as well as the management constraints to determine the NwSSs and the realizing NS(s) of the required NwSSs. NwSTs and NSDs are then generated according to this mapping. The proposed approach automates the NwS design process and a prototype tool has been implemented as a proof-of-concept. This prototype consists of a set of model-based transformations representing the different steps of the approach. We demonstrate the prototype using a NSliceReq comprising an intent for an enhanced Mobile Broadband (eMBB) NwS and an intent for a remote gaming application.