## 1 Introduction
In [5], technologies and design principles that will make it easier to overcome these difficulties are explained, and it is stated that traffic management should be performed with an intelligent mechanism to ensure continuous quality of service for users. Using SDN technology in 5G, programmable, flexible, and modular logical networks can be created on the same network infrastructure. These logical networks are defined as network slices. Each network slice represents an isolated, end-to-end network designed to meet the different requirements of a specific application, as opposed to the current 'one size fits all' architectural approach [6]. SDN technology aims to centralise network control by separating the data and control planes that are combined in traditional network architectures. The separation of the control and data planes is achieved through a well-defined programming interface between the network switches and the SDN controller. This Application Programming Interface (API)  
Figure 1: End-to-end 5G network slicing architecture. allows the controller to directly control the data transmission activities of data plane devices. The most popular API is the OpenFlow [7] protocol. An OpenFlow switch contains one or more packet processing rule tables. Each rule that matches traffic performs specific actions (drop, forward, replace, etc.) on the traffic. Depending on the rules loaded by the controller application, the OpenFlow switch can be instructed by the controller to act as a router, firewall or load balancer [8]. While SDN architecture is the technology that enables network slicing, it lacks key capabilities to efficiently manage the lifecycle of network slices and their constituent resources [6]. In this regard, an NFV architecture [9], which manages infrastructure resources and regulates the allocation of resources required to deliver Virtualised Network Functions (VNF) and network services, appears to be the ideal solution [6]. NFV activities are led by the European Telecommunications Standards Institute (ETSI). The ETSI NFV Management and Orchestration (NFV-MANO) architectural framework defines the following functional blocks:  
* Virtualised Infrastructure Manager (VIM);
* NFV Orchestrator (NFVO);
* VNF Manager (VNFM). The VIM is responsible for controlling and managing the computing, storage and network resources of the Network Function Virtualization Infrastructure (NFVI). The NFV orchestrator has two main roles. The first is to ensure the correct allocation and use of virtual resources in the network, and the second is to manage the lifecycle of network services. VNFM is responsible for the lifecycle management of VNF servers [10]. In the 5G network, the user needs to select the appropriate network slice and receive service from that network slice. This is where the Network Slice Selection Function (NSSF), one of the core network functions, comes in. NSSF receives network slice information from MANO via the north interface. By looking at the network slice information received from MANO, the network slice information to be accessed and the network slice information in the subscription information, the user can access the default network slice or the authorised network slice [11]. To express this functionality in Figure 2, the UE (User Equipment); DU (Distributed Unit); CU (Control Unit); core network components (NSSF-Network Slice Selection Function, NRF-Network Repository Function); UDM-Unified Data Management; PCF-Policy Control Function; NEF-Network Exposure Function; AUSF-Authentication Server Function; AMF-Access and Mobility Management Function; SMF-Session Management Function; UDR-Unified Data Repository; UPF-User Plane Function; and transmission network; the end-to-end SDN and NFV-based 5G network architecture is shown. In 5G networks, hardware-dependent devices in the transport network can be virtualised and managed via SDN controllers and MANO on general-purpose servers.