  The customization of services in Fifth-generation (5G) and Beyond 5G (B5G)
networks relies heavily on network slicing, which creates multiple virtual
networks on a shared physical infrastructure, tailored to meet specific
requirements of distinct applications, using Software Defined Networking (SDN)
and Network Function Virtualization (NFV). It is imperative to ensure that
network services meet the performance and reliability requirements of various
applications and users, thus, service assurance is one of the critical
components in network slicing. One of the key functionalities of network
slicing is the ability to scale Virtualized Network Functions (VNFs) in
response to changing resource demand and to meet Customer Service Level
agreements (SLAs). In this paper, we introduce a proactive closed-loop
algorithm for end-to-end network orchestration, designed to provide service
assurance in 5G and B5G networks. We focus on dynamically scaling resources to
meet key performance indicators (KPIs) specific to each network slice and
operate in parallel across multiple slices, making it scalable and capable of
managing completely automatically real-time service assurance. Through our
experiments, we demonstrate that the proposed algorithm effectively fulfills
service assurance requirements for different network slice types, thereby
minimizing network resource utilization and reducing the over-provisioning of
spare resources.
